We were stuck on Garalon for ~50 wipes. That was ~10 hours of attempts which was three weeks raiding, for my guild.
Without an enrage we would have beaten him on the 10th attempt and he would be a free loot boss.
With the enrage his death brought a passionate emotional outburst and as a young guild bringing down Garalon (and sticking together through weeks of stalled progression) really brought us together.
It turns out that we were doing the legs like idiots, of course. Once I read a leg / dps timing strategy on these forums we started downing him with 2 minutes to spare. Oops.
Enrages are important components to a fight. Without one we certainly would run 4 heals on every encounter. Why wouldn't you?
Honestly, I haven't seen a N mode only guild that pushes content that hard. With a few tweaks here and there (replacing bad players, everyone showing up knowing strats, optimizing rotations for the fight, etc) you could easily be beating the harder heroics. So much of it is simply about persistence.