I have a Bathmate Hydroextreme 9 that I’ve used for years on and off and gotten some gains from it though the MityVac is far superior to the Bathmate since it has a gauge and you can buy different sized chambers for it. And of course the quality is much more professional compared to the plastic Bathmate.
I now both look at think of the Bathmate as more of a toy, if you can afford it I highly reccommend you buying the MityVac.
And yes had the problems of my nuts getting sucked into the Bathmate a few times since it’s a bit too wide at the bottom though with my more fitting MityVac chamber that’s not even close to happening.
I’ll probably never go back to using the Bathmate as I find the MityVac that much better and easier to use. Only takes a minute to clean up the lube afterwards and you can of course use it in the shower/bath which is a big bonus.
Though I’ve found out I prefer pumping dry, with lube as I didn’t even get any mentionable fluid retention, and I go hard in the MityVac.
Do yourself a favor and buy a professional pump like the MityVac is, with a fitting chamber and a gauge. I’m not trying to sell it to you this is just my honest asessement, opinion and experience with the MityVac speaking here.