I have a couple of Harris bipods, one with the swivel, and one without. I think they are well made, and I would buy another one. I don't know about others, but I think most of the time you do get what you pay for.
If you are going to buy one, and are turned off by the price difference between the swivel and standard, I would save and get the swivel. I didn't think I would really appreciate it that much when I bought my first one until I fired a gun that had a swiveling bipod. They are much nicer I think.
Also, think about how you are going to be positioned to do your shooting. If its off the bench a lot, 12" might be too high. It is for me personally, and the bench height of the ranges I usually go to.
If you get one thats not a Harris, let us know what you think of it.