I'd have an US but these days I hardly ever use it. Nowadays I just spray the stone with Windex then brush with a baby toothbrush, rinse with warm water, pad dry with a lint free towel, dip in alcohol, airless spray dry...All done in < 2 mins!
I have good luck soaking mine in jewelry cleaner or Dawn dishwashing soap then rinsing it with filtered water. I dry it with lint free glasses cleaning cloth.
I have a jewel jet steam cleaner that I'll use once a month or so.
I have a few US cleaners (Cheap ones ~$20 - $40) and since I used it daily I did eventually loosen or shake out some channel set or pave stones so I quit using them.
I have an US cleaner and never use it. It's too big to leave out on my bathroom counter and too much of a pain to dig out, fill, etc. I keep my jewelry pretty clean on a regular basis, so I' don't really feel the need to US cleaner - I would think that it would be more beneficial for someone who doesn't clean their jewelry often and needs more of a "deep" clean in an effort to get rid of any build-up/gunk.
I use a baby toothbrush on my jewelry after it's been soaking in warm sudsy water for about 15 min. There are some spots on my pieces that I cannot get with the toothbrush, though, so those pieces I take into a local jewelry store to have cleaned sometimes. Between those two methods, everything stays clean!