I was bored and installed Ubuntu on an old Pentium 4 desktop and am amazed at how stable and quick it is now. Resource usage is reasonable, and everything seems stable. It's no lightweight window manager, but it isn't as bad as KDE. The last version of Ubuntu I used was the first incarnation of Unity and it too terrible even to imagine. This one feels much quicker and definitely is more stable. As much as I like OpenBSD and intend to keep using it on my main laptop (T60), I am tempted to replace it on my MBP with Ubuntu. I still don't like Linux, but I never thought I'd see the day when I'd come back around to Ubuntu.