I have the Avenger, bought it last summer.
Most is the same I guess, exept that I use 2 projectors.
Calibration should be the same but with an extra projector, it's tedious, but not hard with a laser.
-I used to have the ring on top, but will change to ceiling mount in my new apartment.
It will feel more "grainy" than a monitor, but it's a huge image that is seemless :)
Resolution depends on your projectors, but they have to be short-throw. You get what you pay for, which could be aloooot! 3x projectors, if they are used maybe new bulbs and such, cost quickly runs away.
3x monitors are probably cheaper in the end, but a 270° screen is a 270° screen ;)
-Komodo sim had something going on, but they've not posted any news of that in years sadly, but ask them at Simpit if they have anyone :)
-Delivery was very fast, but I find their communication abit lacking for general questions on facebook atleast, mail has been fast when it comes to product issues, but that's about it, I find them slow to no answer at all considering support.
I recommend them strongly tho!
Building it is very simple, Simpit Warp instructions feel dated, but you can figure out most of it your self by experimenting a bit. It's awesome when you get it right!