50/34 is great in hilly areas. You're either going up or down so the gap in the middle is no big deal. In fact, the mid range gets in the way.
However, I don't think it's such a great combo for places where there is not so much climbing because a moderate headwind puts you in a situation where the big ring is too big and the small ring is too small. For flatter terrain, I think most recreational cyclists would be far better served with a 46/36. You'll can stay in the middle of 46 most of the time and the 36 gives a nice low end with plenty of overlapping gear ratios. Those needing a bit lower could drop to a 34 without having such a massive gap as with the 50T.
Everyone seems to be obsessed with spinning out. In a 46-11 combo, this doesn't happen until 40mph -- hardly a problem for most people. Meanwhile, they don't take care of the low end.
One thing I don't understand is why so many people run 12/25's and 11/23's with compacts. Because of the huge gap between the rings, a wider cassette is called for. A 12/27 or 11/26 make a lot more sense because it increases overlap and improves the low end without changing spacing between the gears that get used the most.