I feel as if all my iOS devices have had their speed improved when they were upgraded to 5.1.
Same for me in e-mail and even imessage. I'm glad im not the only one who noticed a significant improvement!Yes, my 1st gen too has sped up with 5.1 and THANK GOD!!!
It had gotten so sluggish that typing text was often 6 characters or more behind onscreen. It was VERY annoying.
I don't think so.. Restarting never seemed to help me too much. Battery life does seem to be a little bit diminished.When my iPad starts to have crash/stability issues, doing a power off/on will make it stable for a week or so then the crashes come back.
I suspect those who believe 5.1 fixed stability issues might not want count your eggs yet. The power cycle done from the iOS update may have corrected your issues, not the update.
Also, there are reports of reduced battery life on iPad and iPhone from the 5.1 update. Just go browse the apple forums or Facebook.