About the only issue I have experienced is that enhancement doesn't take any punishment particularly well. This means you really cannot tunnel a boss and ignore mechanics as some other classes might do.
Dps wise it can easily keep pace with most classes. Same with elemental.
My biggest advice to you is to not let the shaman community wear you out with the doom and gloom. Frankly they are in a great spot really with too many pointing to top guild policies as the metric to measure performance. Like literally every class they have issues but that really shouldn't put you off a class you like and enjoy.