I just got mine in - thankfully, I can say that their "suggested max size" isn't 100% perfect.
LKS Green Stripe, size 18
I'm 6'00" tall -
Chest: 44.5"
Hips: 46.5"
Shoulder to crotch: 39.5"
Thighs (widest point): 28"
Weight: ~225lb
With most of the previous posters being quite a bit smaller than I am - I decided to roll the dice and get myself one to test the waters and see.
To my surprise - It fits! And, quite well, too.
I just got it in today and had a chance to try it on (over padding). Like Shade77 said, its a 'snug' fit like it should be, but not tight or restrictive. There's a little play in the fabric, and as everybody has also said, its really comfy. No problems at all wearing it (sitting/standing/bending over/etc)...only place that its a little tight is the arm below the elbows, but its not too bad. Its not exactly flattering, since its meant to be skin-tight, but fits pretty much exactly like the other photos that people here have posted.
Its definitely possible to get it on and off by yourself:
To get it on, I had the entire sleeper down around my knees and zipped it to just below where my shoulders would be. Slid it up, over my hips, and pulled it up to my chest. From there, arm in, over one shoulder...then repeat with the other side. Once it was on, pull down in the back with one hand, and I used my other hand to push the zipper upwards as high as I could get it (it takes a bit of contorting). After that, with one hand, grasp the back by the neck, pull it (gently) as far up as I can get it, and the zipper's within reach. Zip up, fix the tabs, and done!
To get it off, its just the reverse.
I haven't washed it yet, though...so no telling if that'll change after the first wash (and shrinkage).
Anyways, hope that helps somebody!