I just got my UV777PBK about a week ago and I love it, but I just fell in love with a new Non-Universe/JEM guitar last night. I feel like I'm cheating on my new bride on the honeymoon.
It all started when I decided to make a less expensive Flo- I purchased a Jackson DK2 body and neck, installed a Jackson FR trem I already had and installed an EVO bridge pup (purchased from Eric's Guitars) and an EVO/Jem single coil (purchased on evilbay) in the middle position. I plan to install the Fernandes Sustainer, but I haven't gotten it yet. I decided to install the Evos to check out how they sound while I'm waiting for the Sustainer.
Man, this guitar rocks! The Evos sound great in this body (Alder) and the neck plays like buttah. I really, really like the jumbo frets. It also stays in tune really well ( a lot better than the UV, but that's because I bought it on evilbay and it came without strings- I don't think I've got the trem balanced properly yet).
Anyway, I still love my UV, it's just different and will be used for different sounds. I have to admit- the Jackson looks pretty cool, but nowhere near as cool as a Jem or Universe. I'm planning on getting a Jem 7VWH after I get my year-end bonus, and maybe a Bad Horsie BRMR if it's a good one. That should cover most of the Vai sounds.