I have a Sprint Motorola Razr V3M
1.How is the sound quality? I download songs from my Mac to my cellphone via bluetooth. I found most of the songs transferred with excellent quality... however my Green Day "Dookie" album ended up sounding very "tinny". Then again, I think most of the quality is from the headphones and not the player. An added benefit is that my cellphone's built-in speaker is quite loud and is audible while I am biking (although I just use the headphones).
2. Battery life. The battery that came with my cellphone sucked. It couldn't even last 12 hours on standby. I think I got a defective battery, but the Sprint store wouldn't exchange it, da *******s. I bought an extended battery from Verizon and the battery life is perfect for my needs. I have used my cellphone for GPS, conversations, and MP3 on a 4 hour bike trip without even losing one battery bar. HOWEVER, battery life on my iPod is still quite a bit longer than my cellphone no matter how you compare it.
3. Downloads. I use the bluetooth feature on my Razr and on my Mac laptop. I can sync music, videos, photos/screensavers, contacts, and calendar without any additional software or fuss. Sprint allows this, but Verizon hobbles their Razrs so they can't. I love all the features on my Sprint Razr, but there is still tons of room for improvement. My calendar and alarm clock functions are worse than ****ty. 90% of the time, they won't go off on time (if at all). To listen to music, the software has to boot ALL the songs into memory, which can take up to a minute or two. Once that's done, it works fine... but it's still a hassle to have to wait. Also, I like audiobooks and my cellphone's software can't save your place. If you exit out of the song/audiobook/podcast, you gotta start over from the beginning later.
3.5 Verizon has the best customer service I've seen and also sells a lot of the various paraphenalia I've needed, but they hobble their phones so you can't download stuff from your computer easily. Sprint makes it very easy to download your own material... but their customer service is an exercise in futility and frustration.
4. When I was looking for cellphones, I looked for Mac compatibility. The LGs were not compatible in the slightest with Macs when I examined them (it might have improved since then).