OS X Mavericks will have a feature I always wanted in Linux: Independent spaces for each monitor!
In Gnome (at least when I left it, but I don't think it has changed) and previously in OS X, switching to a new virtual space will update both monitors. With this update you choose virtual space independently for each monitor, and let one stay at — say — the logs window, while you change the space on the other monitor.
I don't remember the specific setup (or what it's called), but you can have that in Linux. The problem is that then you can't drag windows from one monitor to the other, though that may also be something that can be configured. Because of that I never liked independent desktops in Linux, but I like how they implemented it in Mavericks.
This changed in Gnome. The last time I used it a year or two ago, the default is to keep one monitor constant and switch desktops on the second monitor as you wish.
In Gnome (at least when I left it, but I don't think it has changed) and previously in OS X, switching to a new virtual space will update both monitors. With this update you choose virtual space independently for each monitor, and let one stay at — say — the logs window, while you change the space on the other monitor.