
I have the booster bath and have found them very good. When I first looked into them I thought they seemed incredibly flimsy but they are in fact quite stable.
I had a large one in my previous house and that coped well with even quite large dogs (think overweight labs). I initially had a plug-on-to-taps shower attachment in my utility room and put the drainage hose out of the back door. I then transferred it to a garage with a proper shower and drainage.
My current set up is that large dogs are bathed in a "human" double shower (it does involve bending) and with smaller dogs I use the booster bath which I bring in to the shower room and plonk on top of the shower tray. Works well for me.
I guess it depends on your set up.