We recently upgraded from a Samsung Q90 to a newer UST projector. After some research and great assistance from Joe Schodowski, we decided to pair it with the SI 5 Series screen. In 35+ years of marriage, my wife has never, ever, been impressed with any AV product that I have sweet-talked her into... until now. It is immensely satisfying to finally have your wife say... "yeah, that is really nice".
The SI 5 Series (with our UST) has really impressed both of us - I expected it to look good, but it has truly exceeded my (our :)) expectations. UST projectors get a lot of "they'll never be as good" reviews, but I'm quite happy with our setup. I used to make slight jokes when people talked about projectors and used terms like "immersive" and "cinematic experience", but I'm now guilty of that myself :). I don't have anything to compare it to, but I would highly recommend this screen (and a UST) to anyone that's in the market.
Assembly only gets a "3/5" for me. Shipping was awesome, unboxing and putting the frame together was simple. However, attaching the screen to the frame with the supplied "bands" was a serious pain (make sure to orient the frame correctly or you'll end up with the insignia upside down). Finally, attaching it to the wall was easy as well. The picture is so good, you'll slowly forget the "pains" of assembly, but if you are short on patience, think about having someone else install it.