I love my enV. It's not the slimmest phone, but I can still forget it's there when it's in the belt clip. I'm a big guy though, so to me smaller isn't always better.
I've got the extended battery, and if I don't use bluetooth too often, I can get 6-7 days out of the battery. I get this battery life while talking 300-400 minutes, web browsing 150-300 minutes and texting 200+ messages a month.
I wouldn't say that MP3 playback is loud, but it's decent for giving some background tunes while working in the garage as long as the phone isn't too far away from you.
You can use MP3s as ringers if you load them on a microSD card and send them to yourself via multimedia message. Even if you don't have a data plan it's still way cheaper paying for a multimedia message than buying an overpriced ringtone. Plus it's not hard to do--if you check
www.howardforums.com the topic of putting MP3 ringers on phones has been beaten to death.
The only thing I don't like about this phone is that the speakerphone function only works while the phone is flipped open. Not really a big deal but something you should know before you buy it.
For good phone feature comparisons, check out
www.phonescoop.com - plenty of good side by side comparos as well as site and user reviews. Also check howard forums (
www.howardforums.com) for info on verizon phones.
Hope this helps!