I dropped iTunes and use Winamp now. I like it better than doubleTwist. It seems to have more features, and I don't like that dT looks just like iTunes.
The usb syncing works fine in Winamp, but the Wifi sycning, although free, does not have all the kinks worked out yet. It's it and miss, but they have been active with the updates.
I use Google Listen to download podcasts straight to my phone. Since I don't need the desktop app for podcasts, I actually don't have to sync all that often. I also buy music with the Amazon mp3 app. With Winamp, it detects "new" songs and you can copy them from your device via usb or wifi to your machine easily. That is pretty slick.
I use PowerAmp for listening, also.
Yes, extended listening is a drain on the battery. I have a a 2250 extended battery. I recommend putting it in Airplane mode to turn of the juice-draining radios if you are going to keep it awake and listen to music.
I use it for car listening, mostly. I copied my music to my work computer from my sdcard and have Winamp running on my work computer.
Winamp will import your entire iTunes library with playlists and ratings.
You can create "Smart Views" which are like "Smart Playlists."
There is a learning curve for it, though.