Good luck in the draw and hunt, regardless of which area you chose.
As others have mentioned, there are slammer bucks taken from both areas each and every year. I have hunted the Gunnison basin and Eagle county areas a few times each. Before 2008, I would have told you to hunt the Gunni basin. Probably, because that is where I was spending my time in turning up good bucks. But I have to think someone could turn up a good buck in almost every unit in Colorado, providing they dedicate the time, and patience to do so.
Hope your decision and season plays out well for you!