Yup, you're probably the only one...
IME, the sight tube/glass is a huge help. I can see, at a quick glance, what my volume is. That helps me to decide if I need to add time to the boil, or not. I don't need to use a stick, into the keggle, to see what the level is. IME, that's far too inaccurate. For one thing, you need to be 100% sure to hit the same spot (to get the reading to line up proper). For another, I use a hop spider, so using the middle is out. Using a keggle also means I have plenty of head space, and I keep an eye on the keggle. I do have one of the temperature sensors sitting in the wort, as it gets up to a boil (and during the boil, removing it only once the batch is in fermenter). Using the Fluke 52II also means I don't need to worry about the dial thermometer being out of adjustment. Or adjusting it for use the first time. IME, that's more trouble than it's worth.
Even when I start with more wort, for either a larger batch or longer boil, I'm safe from boil-overs (currently).
As for cleaning my sight tube. That's pretty damned easy. It's connected to the keggle via TC clamps, so easy to remove/install. It has compression fittings (using o-rings) to hold the glass tube in place, so that's also easy to remove and clean. I have a nylon brush that easily goes into the glass tube to quickly clean it (when needed). Using borosolicate glass tubes means they won't stain/discolor like the plastic can/will. Plus, they're safer to much higher temperatures. I also designed my sight glass so that it can recirculate back into the keggle. I was a bit concerned with the ones people were installing, that had open tops. I also have a shield around the glass tube, to protect it from stray hits, and give me a way to mark it for the levels. Right now I just have sharpie marks. I'm planning on using the stickers I got from Bobby_M soon.