First let me say that I really don't give a damn WHAT method you chose, as long as you enjoy yourself, make beer you like, and are happy. As a brewer who has made beers for 35 years, and has brewed with 3 vessel, BIAB, All-in-one, HERMS, and recently lost ALL of my equipment to fire and thus could choose ANY system or style I liked to rebuild my brewing, I would like to make a couple of observations on this topic - play a little Satan advocate if you will:
For starters, I have not seen this much rationalization and positive affirmation in one place since Stuart Smally was a character on Saturday Night Live! ANYTHING so completely free of flaw, and so wrought full of virtue, simplicity, and utter excellence RARELY needs such devoted and wholesale defense! Odd.
ALL BREWING SYSTEMS - Have issues. All require some attention to water chemistry, can produce unwanted characteristics, and need attention at differing points and times. ALL can and do produce fine beers. ALL can produce excellent beers, and are far more dependent on the cook and the ingredients than the pots and pans used to make it.
Let me look at some of the downsides I EXPERIENCED in my home brewing with BIAB, and why I dropped it to begin with and why I had/have ZERO interest in it as i rebuild. (I know some of these things will come as a shock to many of the readers on this thread since once again a good common sense thread about BIAB, has morphed into an inclusion of LODO, and has gradually devolved into a religious tome wherein the miracles of this system are rivaled only by the resurrection of Lazarus, and maybe the whole loaves and fishes thingy!
I heat my water for mash in a 5 gallon pot on the kitchen stove. I mash in a 10 gallon cooler on the counter. I sparge into a 10 gallon pot, take it on the porch and boil away. I heat a bit more than half my water for the mash. It does not take long on the stove. I crush grain and get parts together while it warms. I mash for an hour which is MORE than enough time to heat sparge water to temp. This sits a few minutes in the mash tun before draining. Pretty typical sort of 3 vessel.
Now when I tried BIAB I had to heat ALL the water at once- but still had to do so on the stove. I could have bought another expensive 10+ gallon pot to do this BUT it would not fit on the stove anyway and even if it did it would have taken a whole lot longer to get it ALL up to temp. Getting the 20 gallon BIAB pot on the stove was out of the question entirely! SURE i could have built a big expensive brew room with heater big enough to heat ALL the water at once in the 20 gal. but I don't want to. SO I had to heat it all in three pots (Still more gear for this SIMPLE system) Then I DID have to buy a much bigger brew pot because my ten gallon pot was not big enough for am huge bag of grain and ALL the water. So more expense AND a BIGGER pot that is more of a pain to store, clean, handle, move when full, etc. Then of course there is that whole LIFTING IT THING. So now I need to install a pulley in my kitchen ceiling (WE already established I do not have time, money or desire to build a dedicated brewery room) I do not WANT a pulley in my kitchen ceiling. So I either need to recruit someone to brew with EVERY TIME I BREW, so we can both stand there like fools holding a hot bag of wet grain. OR jury rig some sort of ladder, tri-pod or other system to hold a pulley to life the heavy wet bag. WAY convenient so far. And so far all i can see i have saved for TIME is the short period of waiting for the sparge to be done the second time, so a few minutes. (I lost all these few minutes dragging the clumsy ladder rig in and out of the house and fussing around with the pulley) So now i have wort, and I gotta tote that big ass 20 gallon pot out the door to the porch to boil. The old 10 gallon was awkward enough but the big pot is a real pain. I prefer to brew alone - and like to brew on MY schedule, not dependent on having someone else on hand all the time. But now i am horsing around giant pots that don't get lighter as I age! They will not for you either. Still, boil and pitch and done!
So now the clean up - AH YES the clean up, where BIAB REALLY kicks ass! So in stead of wiping out my ONE water pot and storing it, I now have three. STILL is is only water, so easy. Then I have to go outside and dump my grain out of the cooler, and rinse it out with the hose. THAT takes pert-near 5 minutes. When I did BIAB, I had to drag the bag outside and dump it, then clean it out. Thing is AFTER draining the wort initially, I STILL had a messy bag hanging there, and it was still dripping. SO I needed a pot to catch the drips which had to be cleaned (another item to clean) And it took a good half hour to get ALL THE CRAP off the bag, and get the bag washed up. So I cannot see the clean up advantage to BIAB, I gotta clean a tun or a bag one way or the other, and I need something to catch the drips or else i have to mop up the mess when done. After the boil, I gotta clean a big heavy 10 gal pot or an even bigger heavier 20 gal pot. Point is, I still gotta clean up pots and bags and utensils and saying that BIAB is less dirty, easier clean up, simpler, is just self- deluding.
So far I have had to buy more water pots, OR try to fit a big old 20 gallon pot on my stove (Even if I could do this and was willing to wait half a day for it to get to temp, I still at SOME POINT need to move this WHOLE POT full of water or i can't use my rigged up pulley to lift things. So for necessity I HAVE TO heat the water separately and add it to my BIAB pot.) I need to clan a bag or a mash tun, I need to move a big pot or bigger pot to boil. I have to clean my pot. I do not yet see any savings on cost or convenience - NONE
Now you can argue, that I am twisting some things, or that my circumstance is different than yours - True to some extent on both counts. I COULD put my heavier, more costly 20 gallon pot out on the porch and heat it there. I COULD rig my jury rigged ladder pulley outside over the top. Then I could just heat in one pot, drain, boil, WOOHOO!!!! But I still gotta buy heavier more expensive gear. Rig a pulley. Put a catch pot under the drippy bag. clean out a mash bag. AND adjust my grind, recipe, water chemistry, etc from all my old recipes. Now ALL while freezing my ass off 8 months out of the year on the porch. BIG FUN THAT! Thank you BIAB preachers! Thank you!
The fact is as I said to start: ALL SYSTEMS have negatives. All have positives> If yours fits your environment, lifestyle, brewing needs, etc. THEN ENJOY IT and be happy. But I would suggest that endless rationalization and defensiveness really does nothing to further the cause for ANY brewing style. And it feels to me like more than ANY other system the BIAB seems to foster a sort of zealous insistence that new brewers must join in and old brewers must convert than anything else i have seen. In my circumstance/environment I found BIAB at BEST an inconvenient PITA. It does not mean you will or should. In a different circumstance I might find it a joy. When I had a large dedicated space, I also had a HERMS system and did not mess with BIAB, perhaps in that environment it would have been great. But in my original kitchen set up, then in the kitchen set up at our home that burned, as well as the one we are in now - it offers nothing but bulky gear, and mess. I brewed for the first time since the fire on a hotch-pot assortment of a 3-vessel system that friends and family fixed me up with as a surprise! Currently it is THE BEST system I ever had! Had I had the spare cash, I probably would have gone to an all-in-one of some sort. I had an anvil for a short period that I sold to a nephew before our fire - I liked it. But the igloo cooler, water pot, 10 gallon boil kettle works like a charm and fits our current kitchen and porch just dandy.
NO SYSTEM is perfect- use what you like and do not work so hard to prove yours is best. It is really only BEST for YOU. There is a difference.