There are several distinguishing characteristics that differentiate the Millennium from most stands. First is the height. There are lots of cheaper stands that are fine but many don't have the same height. I find height important for archery season when you need to get inside 30 yards for a high percentage shot. Most of the other stands that do have that height use a support bar between the middle of the ladder and the tree. This limits placement to trees that are quite straight. With the double ladder bar stiffness of the Millennium, you have more flexibility in placement. I've seen other stands that are as comfortable as the Millennium, but none that are more comfortable and stable.
The big downside is the weight and cost. If you move stands regularly, the weight can be a limiting factor.
Having said that, I've tried a number of tall stands that are less expensive. One was a Muddy Odyssey XLT with tree Lok. The tree Lok was of no value to me because of how I erect stands, but it didn't hurt anything. It has a lot of movement and play and is not nearly as stable as the Millennium. The worst thing is the seat back. While the seat is just as comfortable for me, the seat back is so straight up and down that my back can't take it for long. I'm much better off with a seat back that has a slight recline.
Another tall stand I tried was the Muddy Stronghold 1.5. While much more huntable for me than the Odyssey, it does not have the stability or weight of the Millennium.
Thanks,
Jack