I have owned 3 maual cars in the past 14 years and none of them have ever had a problem with the clutch wearing out. If you know how to drive one it should last for a really long time. If you are passionate about driving and being completely in control of all aspects of your vehicle, get a manual. If you want a cruiser for traffic maybe get the auto.
n I don't know anything about the BMW SMG but I found in my wifes old A4 that the tiptronic shifter option was fun (yet unltimately a novelty) for the first 2 times I drove it and then I found myself always in automatic which was over-driven like hell, the thing was between 1 and 2000 rpms. You had to stomp on the gas to get the thing to drive in any spirited fashion, which it was capable of. With my manual in the Bimmer I seldom shift past 3rd and can stay in 4th on the highway in regular driving conditions (65mph and below) without running the RPMs obnoxiously high. I guess I just prefer the manual. Having a clutch is the way to go. IMO the SMG/ paddle shifters/ tiptronic/ whatever were meant for Indy cars, not German road cars. Also, no one will ever question your decision of getting a stick, not that you should care what anyone else thinks about your car. I say get the manual. Unless you have long commutes of stop and go.