Had to do a hard reset to fix the problem after talking to Samsung. Beware, as they admit it's a random problem that affects a significant number of their phones. Back your data up, I thought I had between Lookout and Google, but alas not all of it.....
Having done it, my advice is don't bother until the bugs are ironed out. The differences are ostly cosmetic, I see no improvement in battery life, nor the management of wi-fi and mobile data reception. If nothing else, I am amazed at the number of really irate people on the various phone forums (an odd "interest" in its own right perhaps) who are so desperate to get their updates, and threatening to change carriers / phone brand!