Thanks. Yes, I'm quite sure I want 5.1.1. My only reason for wanting the to be able to restore to 4.3.3 was as a failsafe, in case something went wrong with the 5.1.1 upgrade and jailbreak (like maybe some of my crucial MIDI apps stop working or something else flakey starts happening), it would have been nice to have the security of knowing I could at least put things back the way they were. But I guess I'll just take the leap!
Hi Scott,
If you have SHSH blobs for 4.3.3, I believe you should be able to restore to that version, although you may need to use an older version of iTunes (I typically download the iTunes version that was active at the time of the iOS version release). My understanding is that you can restore any pre-iOS5 versions as long as you have the SHSH blobs, as Apple did not implement APTicket system until iOS5. Once on iOS5, however, you have to deal with APTicket, which presently means you can downgrade to lower iOS5 versions using iFaith 1.4.2+, but not on devices with the A5 chip (or newer), which means iPad2 and iPhone 4S. That said, though, I do think going back to 4.3.3 remains possible, even after upgrading to iOS5 (but only if you have the blobs).
At any rate, I just "took the plunge" myself, going from 4.3.3 to 5.1.1 on my iPad2 (Wifi only). JB with Absynth worked fine.
[Moderator edit: Removed major parts of this post because of references to piracy. Seriously, people - read the rules! Any discussion of piracy is neither condoned nor tolerated here. Not only is it against our rules, piracy is illegal. Quit stealing apps and don't be a pirate! This is your only warning, zathras.]
Lastly, even with 5.1.1, I did notice significant battery drain. I didn't set up / don't use iCloud, and I turned off the "Find my phone" feature, but this did not help much. There are numerous articles about this issue out there. One in particular mentioned that disabling notifications except for the apps you really need, resetting the network settings, and rebooting seemed to get him back to near-iOS4 battery usage levels. I have done the same, with (pleasantly) the same results.
Hope this helps, and good luck!