My experience with stand alone units is in South America, and lets just say, if you turn the tap too far, you will find yourself getting a good "internal cleanse". There are places of course with low pressure, but any of them that I've used on the regular have been almost too strong. Slouching on one, half asleep at 3am and getting a shot directly to the clit is not as fun as it sounds...

The stand alone ones I've tried though have all lacked pressure. They have had lights, heaters, UV, self cleaning and all sorts of fancy things, but the feel like getting sprayed by a water bottle you'd use to keep a cat off the counter