Forever sold on the ultra-short throw life. This is the only way to fly!
My ONLY complaint about the 100L5G is that it still doesn't have direct support for Netflix due to licensing business or whatever. Hopefully that'll be solved eventually and patched in a software update, but honestly, it's nothing that adding your basic Roku to the mix can't solve. It'll handle all the other major services without issue. Are you a Kodi aficionado? Well, friend, this will do the Kodi thing for all your Kodi needs! IYKYK (isn't that what the kids say lately?)
Onboard sound is unexpectedly good, but I've opted to connect to my reliable ol' Yamaha 5.1 receiver (though eventually I need to get a more recent model of it because a 10+ year old receiver sometimes likes to forget how HDMI ARC works, plus I'd like to make use of Atmos capability).
While an installation service was offered, I opted to get adventurous because I never have good luck in scheduling those sorts of things (it's a me problem, not a them problem). If you've got some sense and patience, a slow hand, and a reliable assistant, you can get the screen put together and the alignment procedure done on your own.
Because of the unique construction of my living room, I had to take all the measurements and required distances into account when finding a proper entertainment center to put the projector on. There was no winging it. Thankfully, all these details are provided in both included and online documentation, and I have it as close to perfect as a rank amateur such as myself could possibly get it.
Easy to clean with included squeeze ball or a powered air blower (like a battery powered one, not an actual air compressor or canned air because you DON'T want to contaminate the lens in any manner). Puts off a moderate amount of heat as one would expect, but it's not world-changing. Fans are not audible among other ambient noise. Perfectly watchable with the overhead room light on. Have interfaced a Nintendo Switch (Animal Crossing in 100" HD is overly amusing) and a laptop without issue as well.
For the price point, it's worth your consideration. This is my first UST projector, and I intend to use it 'til it nukes itself from exhaustion. If you can catch it during a sales event, more power to you (full disclosure - I did catch it during such an event, but I'd do it at full price too if I had the chance to repeat history).
About the images: I attached two small pieces of 2x4 to the wall to hang the screen on (plus two more at the bottom for the lower edge to rest against). This gave me a very slight gap between the screen and wall so I could make use of the outlet you see on the very obvious "before" pic. I used a 12" flat plug extension cord to dangle out and tie into a small UPS (I refuse to take ANY risks with this thing!) to power the projector and my audio receiver. Note the very short little shelf I procured to meet all necessary measurement specs.