I've got the Irbis. I like it. Doesn't rattle, well built. I've looked at all the models online, and there are some design features that I prefer in the Irbis over the others. Mainly strength related with extra gussets at the front and 8 mounting holes, but also the recessed hitch receiver and the lower angles seem to work well. It also sits very high and with the 80 coils and 285's, I have 25" of clearance directly behind the tire (all the way across) and 26" at the end of the bumper. The lowest part hanging down are the mounting bolt heads.
I like the tire carrier feature for two reasons: 1) the added clearance mentioned above 2) because I sleep inside the truck. Yeah it looks cool but that is only secondary.
Visibility is impaired slightly but like somebody else mentioned, usually there's enough crap in the back you'd have issues anyway. You get past it quickly.
It doesn't really impede access to the back like I thought it might, its a quick flip of the lever and pull up on the lock. Easy.
A negative I hadn't prepared for is fitting it in my garage. I can, but can't walk around the truck anymore.
Also, if you're doing some hardcore rockcrawling, you need to remove the tire from the carrier. I didn't, and my truck slipped backward off a waterfall and mashed the spare tire on a big rock. It bent up the tire mounting plate, where the studs are welded to. I had to cut it off and I'm making a new one. If you can, have Irbis make that triangle shaped plate out of 1/4" instead of 3/16".
One word of caution with the 4Runner. The rear frame rails are not as beefy as we'd like to think. When you open the tire carrier and pull down on it, the frame FLEXES big time. I can get an extra inch between the bumper and body doing this by hand. Obviously you wouldn't be hanging 200lbs off the back but think about 60lbs or whatever the tire weighs while tearing down a 50 mile washboard or rutted road. I've got some plans to add 1/4" plate to both frame rails from the axle back. That should stiffen it up enough.
I used to hang the hi-lift back there too, but I think from now on I'll keep it inside where it won't get so dirty, and save the 30lbs or whatever from the tire carrier.
Just some thoughts. But Irbis definitely put some thought into his design.