I just read the reviews at Guitar Center, and it sounds like it's hit-or-miss as far as whether you get a good one. To be honest, some of the reviewers sounded like they bought an "open box item" rather than a new one.
In my case, it was the only bench in the store (a Guitar Center, as it happens) with a flip-lid, and the price seemed reasonable, so I bought it. I hadn't researched anything online before I bought it, and wasn't even specifically in the store to buy a bench; I just went there to see what they had, since I'd just moved to the area and was scoping out the nearby stores of interest.
It was easy to assemble. The hinges for the lid have adjustable screws that let you determine how easily it opens, so you can set it such that the lid stays up if you want-- which is how I've got mine adjusted.
To be sure, there are much nicer cushioned flip-lid piano benches out there, such as ones with padded leather seats, but they also cost a good bit more.
EDIT-- I just looked at the two you linked to, and they look nice. I'm not sure about the one with adjustable height-- the picture with it raised up looks weird to me, so I'd have to try it out myself to see how sturdy it is in that raised setting. But the padded leather seat looks nice. I don't think that's the company that makes the nice-but-pricey ones I've seen online, but I can't remember who the other company is; I'd need to check the old posts on another forum to see.