An Eberle X2 will get you by, for not alot of scratch. But, if you're tall, and/or carrying heavy loads, you'll see the shortcomings of the suspension system.
I have a Kifaru Bikini frame w/ 4800 & 7000ci Highcamp bags. The Bikini frame is excellent in all aspects, tough & lightweight, and you can mix/match bags, dependant on your hauling requirements. From the batwing style Nomad, to the simplistic Highcamp single bag, pick what ya need and strap it to a Bikini frame. Be prepared to pay a premium for the quality!
That said, I also have an Exo Mountain Gear 3500 pack arriving today & hope to be using it for our backcountry hunts this season. The Exo packs have gotten rave reviews early on, and were designed by backcountry hunters, for their specific needs. Lightweight, tough, comfortable to hunt in, and the ability to haul a serious load of protein back to the truck. The Exo's price point is quite reasonable, compared to a Kifaru combo. If my Exo passes muster, it's coming to CO in two weeks...