HELL no. Don't update it. I'll bet more than 70% of us have already updated the Infuse anyway, and most of us have it working well. ROMs like Serendipity fixed all of AT&T's battery, application and skin problems last summer.
Have you seen the list of "features" of this latest update we're supposed to be so excited about? lol Just pathetic. And Kies isn't going to let any updates work anyway, so look. Just forget it. They nailed us on this 2.2 phone, just admit it and get on with your life. It's a 512k phone, designed in 2009, introduced in 2010, on the shelves in mid-2011, pulled off the shelves a few months later, and nobody was ever held responsible.
Nobody responsible but YOU and your little 24 month contract lol