Agreed - this is pretty much the only reason MacVim lives on my machines. It handles huge files way better than anything else I've tried.
I can use vim. I know it pretty well. But the inescapable fact is that, for me, it's clunky and requires more thinking than just using a mouse and pointing at something, then typing what I want to type. I use it because I haven't found something better (and I'm sure it exists, I just haven't seen it).