I can't speak to anything other than the Anvil Foundry. I have the 10.5 and there were a couple of selling points for me. First the ability to use either 110v or 220v.
Next was the delay start timer feature. I can fill the Foundry the night before, set it to my desired strike temp and program it to start heating the next morning. When I get up to start my brew day the Foundry is at temp and ready for dough in.
The third selling point was the price. I haven't looked at prices since I bought mine two years ago but at the time it was at the lower end of the price scale. Normally I would be skeptical of the lowest priced of anything but Anvil is owned by Blichmann and I have always had good experiences with their products.
Other positives are that when storing it away all of the parts... tubing, pump, etc. fit inside the unit and I don't have assorted equipment in need of a place to live.
Cons: It is clumsy to clean but then again so has nearly every big kettle I have owned.
There are limitations to how much grain you can mash preventing me from making the big OG beers I like to make. But by using a BIAB bag I can increase the grain bill size above what the malt pipe can hold. However, I bought the Foundry for the specific purpose of being able to brew indoors during the winter and I found that this affords me the opportunity to ferment lagers in my basement. As a result I am not making large OG beers when using the Foundry after all.
Some complain of the power of the pump should you choose to add the recirculation kit. I have had zero problems with that. It doesn't have to be as powerful as the RipTide. All it has to do is move wort from the bottom of the unit back to the top and it does it very well.
The Foundry is not my one and only brew system. I bought mine to solve a very specific problem... not being able to brew outside in my unheated garage during the freezing winters. For me, it is perfectly suited in that role.