I'll continue to use the LFD feature. Anyone can heal/tank/dps a heroic when everything goes perfectly, but it's the situations that push you at your role that really make you think outside the box and make you a better player. Now, that's not to say I won't get frustrated but it really depends on your intentions. If you use heroics for the sole purpose of gearing up then grouping with friends or guildmates will always be the better choice however if you want to push yourself - LFD will be the way to go even if the physical gain is less, you may learn something...