I have a FA SUB (Sport Utility Blind). I'm 6' and 225#. I find it roomy enough, I don't think an extra 3 inches would be much trouble for foot room, if I remember, I think there is a good 6-12" of spare room yet.. It's a bit tight for calling, but I still have room to manipulate them and call at my size, if you are bigger in the chest then me you might have a bit of trouble.
I like the fact that I can leave the SUB all assembled, the foot area is just a bag, so I flop that over the rest and toss it in the back of my short bed pickup. I have carried two of them at a time, fully assembled in my truck, with a tool box too, so for that I like. The larger FA's like the Eliminator Pro Guide XL have to be disassembled unless you have a trailer, or possibly a long box truck. I've been with guy's using the Pro Guide, and found them a lot more work to stubble in. There is a lot more realestate to cover up on them then the SUB, and I don't personally think there is enough extra room in them to justify all the extra work.
A note about the foot bag, in the FA SUB at least, I don't find the lack of frame to be a problem, it is a heavy enough material it stays filled out ok, you don't want to be kicking around in them when the geese are coming in, but I don't see why you would want to be anyway.
I think the FA's are a quality product, I've spent most of the fall with mine riding in the back of my truck, and it's shown no appreciable wear, despite taking a lot of wind in the back of a halfton on all those miles.
In general don't buy a blind that doesn't have two doors, I've hunted out of one with one door, and it takes a lot of work to open it, versus just sitting up through double doors and they flop open. I don't think spring loaded doors are necessary, I have no trouble with the SUB which is not spring loaded. That said spring loaded would probably be just fine as well.
Make sure the blind has a frame in the doors, if it doesn't you are not going to be able to get away with any movement, such as running calls, as the doors will be laying on you.
Make certain the blind has some sort of stubble straps, stubbling in seems to make a world of difference, and if you don't have stubble straps that is a real challenge.
Make sure it has screens to cover your face unless you want to wear a face mask. The FA SUB, has screens that can be folded back if you prefer a facemask.
Pick up some of the silver bubble back insulation that's used for insulating pipelines, put a strip under your seat in the blind, it adds a bit more cushion, and will help keep the cold out when the ground starts to freeze up.
The SUB has a nice padded bar to lay your gun barrel on, if you use guns you care about that is a nice feature, but it's probably something you can modify if the blind you really want doesn't have it.
Get a blind with a floor in it. I've hunted in one that didn't, and you get dirt in everything, which is bad for your gun and your calls.
If you have or plan to get a goose flag, make sure it has side flagging holes, although I think most have that now.
I have not had an opportunity to see or use all the blinds out there, but so far I have not found a reason to regret buying my SUB, which surprises me, because usually when I finally buy something like that, I find the one I really want a week later, but so far I think the SUB is the best blind for my specific needs.
