I have avoided making the jump so far (mind you I'm a tech junkie who used to root my fascinate to get things early).
When I upgraded my Galaxy Nexus to JB, battery would last about 1/2 day on 3G and Wifi only. No BT, no GPS.
I know Directv app will not stream on JB, but I don't use it enough for that to be my reason to stay on ICS.
I guess I'm looking for thoughts on Battery life mainly on JB as well as anything else. I have read some of the posts and am noticing some issues after upgrade.
I can't think of one single reason not to upgrade. This is my opinion, of course. And I've read about people having issues with no mass storage, no more HDMI settings, the absence of the sleep mode option, and the loss of audio effects option under sound settings.
But I never used the mass storage option since MTP still allowed me to copy any files I wanted without issue. HDMI still works fine for me even without the settings, and I never used sleep mode (except via smart actions, which are still available). Also, audio effects are still present, but you just have to implement them through the apps themselves, such as the music app.
The benefits for me are many:
--A much better notification pulldown with expanded gmail messages, which I really like.
--Google Now and better overall voice search. I'm simply amazed at how well it does voice recognition and how quickly it responds. I use this everyday.
--Battery life also seems slightly improved.
--And the camera, while not particularly better at taking photos, takes them faster. So if you're like me and need to take a few shots to get a good one, at least you can do so in less time.
On a personal note, I also like how the status and navigation bar remain transparent when using live wallpaper or a third-party launcher. That was not the case with ICS.