Ok I'm gonna be honest with you. The Omnia 7 is one of the few Windows Phone that I have never touched.
But I'll give you the pros and cons of my Optimus 7 since I had mine for more than 3 months now.
Pros.
1- Battery life: yeah yeah both phones has the same 1500 number but let me tell you something. I charged my phone yesterday at 11:00 AM and gave it fairly good use, tons of apps switching, checking facebook, angry bird rounds, lots of web browser etc... It's 9:52 AM today. Wanna know the percentage of the battery?
Is half. That's right, it can get you like 2 whole days of normal use. ( One day of heavy use )
2- Design: You had seen the phone is person, This phone is just a thing of beauty and it feels nice on the hand, the camera lens are protected and has a nice quality feeling.
3- Lack of issues: I haven't gotten any major bug or deal breaker with my phone so far. Some Omnia 7's have issues so be sure to get the right one..
4- LG apps: Those are not your typical crapware, you won't be deleting them. The work awesome and their Weather app was my choice for a long time.
5-The camera is not as bad as you think, the photos are more than decent and perfect for Facebook uploading. Video recording is also good
Short movie fully shot on LG Optimus 7
Is an entire movie shot on this phone.
6- Games load fast and play smoothly. ( In fact everything is super smooth )
7- Build quality: Is mostly made of plastic but it pretty durable, not squeaks when you hold it, no lose parts and it has a nice metal casing in the back. It also sports Gorilla glass.
YouTube - LG Optimus 7 windows phone still works after car ran over it
In this video there's an optimus 7 that has being ran over by a freaking car, yet still works.
Cons: now not everything is fine and dandy in Optimus land.
1- They are no accessories for this phone: It's so hard to find a decent cover that I feel like I don't even have a real phone in my hands.
2- The metal case on the back is really nice but it tends to make the phone slippery, I have never dropped the phone but It's not because of the lack of trying.
3- The screen is good but it's not Omnia 7 good.
4- HD video is pretty good, nice colors but it tends to be choppy at times.
Anyway it's by no means a high end phone but everything on it works great. Highly recommended.