I don't know what the current exchange rate for two cents in noobie ville to experienced bullshido.net posts but here we go..
Having used all throughout high school I can say that hapkido was INFINITELY more useful to me than tae kwon do was.
The inclusion of dirty shots like elbows to the face, knees the groin, smashing a person's adam's apple made it significantly more useful in 'real world' situations. Being a lightweight I was constantly having to prove myself at pretty much all of the 4 high schools I went to so I had plenty of time to practice. I can't tell you how many times people would come up from behind and bear hug me, grab my arms and try to chicken wing me, or try and throw me around like a rag doll.
So in terms of actual usage, I definately got alot more out of hapkido with it's escapes, locks, and close quarter strikes than the long range kicks of TKD. Though I think one time I palm heeled a kid in the chest. It didn't really do much.
So anyways, there you go. No theory, just experience.