I have had several and have chose to sell the millenium's and the Gorilla's.
They both make a good stand and yes, they are rated for 300lbs.
I use them both although I am normally about 310 in the buff. Never hunt that way though and would guess I weigh about 325 with all gear.
The Gorilla's are great for economical reasons and also quite comfortable.
The Milleniums are by far the easiest stands to hang and are my preferred stands for ease of use and comfort. I pay nearly twice as much for milleniums for my personal use as I do for the gorilla's but just love them.
I own a lonewolf that is rated at 350 and am not very fond of it. It works fine and is well built, but quite heavy and could never get it tight enough to stop squeaking. On top of that, I have plenty of padding everywhere except my rear end and there seat leaves a lot to be desired.
thanks, bigjim