Away rotations have become the "cool" commodity to brag about. It's like the yuppies who have to tell everyone about their summer home(s) or time shares in the Caribbean, or the lady they hire to walk their dog for them. And that if you don't have them or aren't doing an away rotation, you just haven't "made it".
Clearly, away rotations definitely matter for certain specialties (the U.P.R.O.A.D. specialties) and should be strategically selected and planned for waaay ahead of time in these cases. For all others, you should do away rotations only if your spouse or girlfriend is living somewhere else or if you absolutely hate your home institution THAT badly.
I'm spending my 4th year at my home institution and taking advantage of all they have to offer. This requires a glass half-full mentality. If you're one of those people who just like to complain, you'll find fault with everything and will be just as miserable anywhere else.
With the extra money I save, I will go on an extra interview or two, buy a few more things for myself, etc. Hell, I might even be able to afford a new girlfriend.