I have a pair of the really cheap chinese made ones, and they definitely have that "wobble" in addition to the catches either being really loose or really hard to unlock - varying on what the size of the part you have it on is. One thing that I notice is the medical grade ones that I have are all stainless steel - possibly 316L? they are all made in Pakistan, and all function smoothly. If one had to pay for them, I'm sure they would be ridiculously overpriced for hobbyist needs.
I would love to get a few more pairs, specifically some with angled jaws and long handles, so I will continue to check in and see if anyone else provides some input to where to purchase and what to get. If I find some good ones, I will certainly share the info.