I haven't had a match run even that long, much less longer, but I also see no reason why it would bother me if it did. I'd play fewer matches that day as a result, but that doesn't bother me at all, if I'm having more fun in the matches I do play, which I most likely would be.
Knowing what the opponent's deck probably contains is just normal on standard ladder, at least after the first couple of weeks into an expansion. And of course what you draw when will impact things (trust me, I've had Warrior mirrors where my opponent has Mad Genius Boom on 7 and I don't draw mine until much later, it's always sad...) - but your ability to ration out what you need to use when and what needs to be saved for later can make or break control mirrors just as easily as any draw. Maximizing the value you get out of various things can as well: make sure you get 3 cards out of both Omega Assemblies, never pass up the stronger Boom hero powers unless you have no choice, knowing which mechs to grab from Delivery Drones, save your 9+ mana cards for turns when you're stuck with the 1 damage AoE or 3 damage hero power and have no good use for them, don't use Shield Slams on on mid-size minions unless forced to, etc. All of those little things make such matches far more fun to me than any other. Resource management and value over the long term is what it's all about, and that's my favorite single part of the game, personally.
Plus you can get weird moments that don't happen in other matchups, like when you deliberately give your opponent a triple-draw Acolyte of Pain, even though it won't burn anything, because it will accelerate his fatigue. Always fun when a move like that influences a win in the long haul. (Yes, I know Acolytes are not typically used right now, just an example from past matches I've liked.)