The look really good. I'd give them a 3/5 on the sturdy scale, but mostly I'd say this:
1. I'm 5'9", 145 pounds. I'm the largest person that can probably fit on these comfortably.
2. Putting them together required a drill, and it wasn't super easy. One of the bases had to be a little forced to fit (it worked, but it didn't align super easy).

Overall, I'd recommend these for smaller people who are good with power tools.