FYI - this is my first mac machine after 15+ years of being a big windows nerd. Windows 8 lost it for me, and I'm REALLY impressed with Mountain Lion / Mavericks. So the choice was easy. Anyway, my story: I was at the Apple store to pick up the new 15" pro. However, they didn't have any of the high end 15" left - so I bought the highest 13" model. I can't do 256gb, so the 13" it had to be. After I purchased it, the guy called me and said a store 20 minutes away had 1 15" left - and I could buy both and return the one I don't want. So now I'm sitting here with both the high end 13" and high end 15" - side by side. I thought I would be dissapointed with the 13", but it's not bad at all - and the smaller size is really nice. The caveat is that I have 3 27" monitors for work, and have not had a chance to hook either up yet (I won't be at work for several more days). So I haven't been able to really stress either one out yet. If the 13" is going to be fast enough, I'd definitely rather have that - the smaller size is so much more convenient. I just don't want to regret the speed. I don't run major programs like photoshop - but I have a crap load of programs (browsers, pictures, movies, small-ish picture editor programs, etc) open across 3 monitors. The guys at the store said the 13" would have no issues with that, but I just want to make sure. Then again the 15" isn't THAT much bigger, and it actually feels a bit lighter on my lap since the weight is more spread out - weird. The larger screen is pretty nice too. Not to mention, the battery seems about the same on both - even though I thought the 13" one would be quite a bit better. Very surprising. I seriously can't decide! BTW - I don't game a lot anymore, and if I do it's on the ps3/xbox. But it would be nice to have something that could play light games if I wanted (diablo 3, civ, sc2, etc).