Should have bought this first...

This lens is awesome, and is money well spent. This should have been the first lens I bought, but being the SLR beginner I wound up with a zoom like most people. Ever since I got this lens, it stays on the body more than 75% of the time and I leave the zooming to my feet. Taking available light pictures is so much fun and comes in handy when flash is not an option. This lens is fast, sharp, and feels a lot better than the plastic mount 50 f/1.8...granted it costs 4 times as much. But, I'd still buy it again given the chance to decide between the two all over again. I would say the only flaw in this lens was Canon's use of a micromotor drive in lieu of the ring motor. The lends continues to have full time manual focusing like other USM lenses, but it doesn't feel quite as smooth as a ring motor would. I haven't noticed much difference in focusing speed; although, other reviews have said it is slightly slower than a ring motor.