I've been beating around the Sitka Mountain Hauler 6200 for the last three seasons and so far I am pretty darned happy with it. I was skeptical going in as I usually avoid buying version 1.0 of a product that is significantly different than anything else a given company makes. This was/is Sitka's first foray into the land of big meat-hauling packs.
Coming from a long history of mountaineering and climbing, I have pretty high standards and am pretty picky when it comes to pack design and functionality. I was expecting this pack to be lackluster as compared to some of it's cousins in the regular backpacking market, but I was pleasantly surprised.
The thing that impresses me the most with this pack is how well it carries under a significant load. This is due in large part to the design of the frame and the internal load shelf/sling design and positioning. At one point this past year I had a whole sheep (meat and head that is) in it along with my day gear which I thought to be about 130 or 140 pounds in total. The pack bore it very well and didn't compress, warp, or buckle. The pack positions the bulk of the load in a manner that make it much easier to carry as opposed to lumping all of the heavy stuff at the bottom of the pack.
The pack is very adjustable for a variety of torso lengths and configurations. It doesn't have a lot of "extra" stuff on it like pockets, straps, etc. which is a good thing. I greatly prefer simple, streamlined designs over lots of bells and whistles that needlessly complicate a pack.
I'd say the size is just about right for a 8-10 day hunt where you might expect to carry a load of meat out. Mine fit a sheep, my half of the camp gear, and my personal gear with a little bit of room left over on an 8 day trip this fall.
For it's size this pack is pretty light as well, 6.5-ish pounds. Not bad, but not as light as some.
There are lots of other little things I like about this pack that I could ramble on about, but instead I should probably hit on the few things I don't like.
The material that this pack is made out of is pretty noisy and stiff, especially in the cold. Not ideal for digging stuff out of when you are trying to be stealthy. I like the fact that the material is fairly water resistant, but I worry about the durability of this fabric over time. In particular the bottom of the pack, the part that tends to get the most heavily abraded over time, is a single layer of the pack fabric. Mine is already starting to show some signs of wear and weakening from repeatedly setting the pack down with a heavy load in it. Most pack manufacturers either use a heavier, more durable material on this part of the pack, or beef it up with a few layers.
The material that the hip belt is made out of, or perhaps the shape of the hip belt could be better. For me it was perfectly comfortable with moderate loads, but at about 60lbs and up, the bottom edge of the hip belt really digs into my hip meat. It is as though the bottom edge is just too sharp and should be more rounded to avoid cutting in.
As I mentioned above, I like the very simple design of the pack. It is basically a main compartment, a back compartment, and a lid. I wish the back compartment were split into two like on the old Dana Designs Astral Plane and Terraplane packs. I like to have one quick access pocket back there for the spotter and another for gear as opposed to tossing all of my quick access stuff in one pouch and then having to rifle through it all to get anything out.
The velcro compression strap minders are annoying and unnecessary. They get caught on your clothing all of the time and rarely stay fastened to hold the shortened strap.
The side mesh pockets are not well designed on this pack either. It is hard if not impossible to get a nalgene or similar water bottle out of them when the pack is loaded. The top of the pocket is made out of a non-stretchy material that doesn't allow enough expansion to get bulkier items in and out of these pockets easily.
Overall these complaints are relatively minor in the big picture and I have been super happy with this pack so far. It does fill what was a void in my pack lineup for a long time, a backpacking style pack that also hauls meat well. I'd definitely recommend considering it. As others have said, packs are a lot like boot in that proper fit is of paramount importance.
I have a smaller Exo and like it a lot as well. Their waist belts and waist padding suck, but the frames and bags are awesome.
Stay away from the larger Seek Outside packs. A buddy bought one for one of our hunts this year and it shit the bed on the first trip. One of the pack stays tore out of the fabric and we were barely able to make a field repair and limp it along for the rest of the trip. Additionally the compression straps on the pack go around and over all of the access portals (zippers pockets, etc.) on the pack making it very tedious to get stuff in and out quickly and easily. I was very unimpressed really with every aspect of that pack.