Well, I've had my LG Optimus 7 for 3 weeks already. I also have friends with HD7 and Omnia 7.
The device is certainly responsive and the OS is well done. I like it overall, so far. Initially I wanted to go for Omnia 7 (I already have an Omnia 2) but the wait for it was too long.
I don't regret it, but here are some thoughts:
Screen is not the best, the best screen is on Omnia 7. The hard buttons might be useful, but in the same time some people might hate them.
So, here's my take, comparing my LG Optimus 7 to the other 2 devices: HTC HD7 and Samsung Omnia 7
Bulid quality: Optimus7 > Omnia7 > HD7
OS responsive: Optimus7 = Omnia7 = HD7
Screen: Omnia7 > Optimus7 > HD7
Screen size: HD7 > Omnia7 > Optimus7
Camera: Omnia7 > Optimus7 > HD7
Battery life: Optimus7 > Omnia7 > HD7
Price: Omnia7 = HD7 > Optimus7
Recommended 1st WP7 phone: Omnia7 (overall the best device).
Now onto my LG: battery life is like this:
Drain during the night < 5%
Normal usage (10-15 min calls) cca 1 hour play, regular checks on marketplace (wireless on for a while), the battery holds about 3 days.
Good usage: 2-3 hours play, and a lot of wireless, the phone holds upto 36 hours
Heavy usage: 3-4 hours play, wireless on, mail sync, the phone holds upto 16 hours
I personally keep it on low brightness. Camera is ok, but not stellar. For casual shooters works just fine.
Let me know if you need anything specific tested.