I've got the 50-34 FSA mega exo SLK compact on my bike now, too. I thought it was great as I wasn't winded on my way up the San Gabriel Mountains northeast of Los Angeles.

Since I live in the Foothills, I need such a crank. The best part about it though, was that I was much more willing to tackle uphill climbs, which are still a little difficult. With the compact, though, I want to attack the mountains, and I don't have to worry about busting my knees. A bike shop owner suggested I get the compact. He was right, and I thank him for the advice.