Screaming Eagle, hands down for me!
All steel (except seat which is padded wood), chain instead of nylon strap (won't deteriorate or be chewed by squirrels or porcupines), bites into tree to give a very stable stand – no wobble, seat height is perfect (on most commercial stands the seat is too low), both platform and seat fold up to prevent accumulation of snow/ice and to keep seat dry and make it less visible when not in use, virtually indestructible and theft-proof with good padlock, choice of large and small platforms and seats, and can hang a VW Bug from it.
One, and only one drawback is that they are a little on the heavy side (I think the large one is about 18#). However, this adds to stability, and is not a problem if you carry it on your back with a couple removable shoulder straps.