I own one of the roll-about types that attaches to the sink. I love it. It gets dishes cleaner than many of the built-ins I've used over the years.

Although my unit is larger than the counter-top versions, the principle is the same: it attaches to the faucet, you turn on the hot water, plug the power into the mains and away you go. One caveat: to attach the water hose on mine, I had to swap out the aerator nozzle on the sink for a quick-lok fitting. It was a matter of 2 minutes with pliers (protect jaws with a rag to prevent scratches) but make sure you're cleared to mod yer spigot.

We had a roll out unit like Triode mentions in college - it was great as long as you had a place to store it. My friend got one of the smaller, true counter top style machines to sterilize bottles after she had her first baby. It worked well, but they ended up installing a full size machine when they were getting ready to have their second. I think it was more an issue of quantity, not quality of washing at that point.

I briefly owned the roll-around Haier unit pictured, but it broke after the first use and was unrepairable. I had to have it taken back, and bought a similar unit made by GE. This is now in its third year of life and it's fabulous. Doubles as a butcher's block too. I even converted occhiblu to the dishwasher way.

Never tried one of the countertop units, though. I suspect the microscopic capacity would be kind of annoying.

It is true. I have been converted to the dishwasher way.

But, really, I am only converted because, as Triode points out, we have room for the thing. I was getting ready to exercise a veto vote if we ended up with a teeny kitchen, because I hate losing floor space in work areas.

Whereas I'll plumb the thing into the living room if I have to, should I move into an even smaller kitchen. (argh, san francisco) I've never felt such fierce allegiance to a home appliance before. (mine's a Kenmore, btw) And the surface does make a dandy worktop. In a stroke it doubled my available surface area.

I am more interested in the actual countertop units since I am only washing for 1 1/2 and my kitchen measure all of 5' x 8'.

We had one like the "Carocelle" for awhile. I can't say it wasn't functional, but there was quite a bit of pre-washing involved if we wanted stuff to actually get clean. Dishes only, forget about pots and pans.