Who uses them what do you think?

I use one rom Harbor Freight. Looks identical to the smaller model from Hornady (and several other mfg). Waited for a sale and used a coupon, got it for something like $60 including a 2 year replacement warranty. Works great. No issues. Just ran a couple of batches of 6xc through it last night. Only thing it won't completely clean usually is the primer pockets. The crud is just too stuck there.

Have the Hornady 2L model. Works great on gun parts. Wife cleans jewelry in it. X2 on Strongbad comments but I really like mine

For my own a run through the H2L is fine after range day. But if I'm able to get a lot of RPU (range pick up's) I'll run them through the old vibratory tumbler with mineral spirits to clean all the old crud and gunk off them first.

I take the basket out of mine and use purple power for the solvent,full strength.Works great. it gets the primer pockets clean too.

I have the HF model also I think I paid about $60 out the door with a sale & coupon.
I make my own brass cleaning solution from Lemmi-Shine and Dawn Ultra Platinum.
You must be careful not to use cleaners that contain ammonia, which is quite a few.
I make a gallon at a time 1 Teaspoon Lemmi-Shine powder and about 3-4 DROPS of Dawn Ultra Platinum.
Shake it good.
I usually don't let it run in the sonic cleaner for more than about 2 min.
Any more and it will start to strip the Zinc from the brass and it will turn a rose color.