I have the HTC Vivid & an iPhone 4S, and I prefer the Vivid over the iPhone 4S in some ways.
~The 4.5" screen on the Vivid is awesome, the colours are deep and pleasant to look at.
~The internet connection options are AT&T HSPA+, AT&T LTE, and WiFi. The WiFi has a strong signal lock, and the AT&T data network holds fair, and is very fast.
~The battery life is actually very good on my Vivid. I set up "Facebook For Sense", synced 2 times per day, "Weather" is setup to sync when the phone is turned on, and Gmail is setup for push. Nothing synced for "Stocks", "News", etc. I also have the GPS & other nonessential features turned off, as GPS can be turned on in the Notification Bar>Settings. And, with an app killer (AppControl is good), killing off
apps after closing them, really helps. With those tweaks in mind, I can easy get about 2 days between charges, and that is with moderate usage (a few calls, texts, emails, running a couple of
apps, etc.).
I did notice the camera actually runs the battery down a bit. I was taking 20 pictures over the span of 30 minutes, and the battery lost 20%. But with a 4.5" screen, a camera, & sending those 20 pictures to Gmail all drinking the battery's juice, that is to be expected.
The battery life on the Vivid actually runs about the same as it does on my iPhone 4S (approx. 2 days) with the same usage, except on the Vivid, it is synced to "Facebook For Sense" twice daily.
All-in-all, the Vivid is an awesome phone, & shouldn't be taken as just the same-ol, same-ol HTC device. This is a HTC phone in a category all it's own. I even prefer it over my old HTC Evo 3D.