I think the biggest problem is upgrades. If you love your upgrades, AS isn't for you, unless you're from Seattle. NW(even with those vouchers), CO, AA, DL will not upgrade you... ever. I decided that it wasn't that important for me so I joined AS Mileage Plan(I still haven't flown AS yet either ).

Now, having become an MVP without flying AS, I just booked a few trips on AS when they were less than $50 expensive. From what I've read it should be better than AA & NW, who I've flown up to this point. I'm looking forward to it! A great FF program is how AS got itself a new customer!