not to complicate the matters more but I'm also curious if anyone know if it's more environmentally friendly to use these smaller machines compared to the bigger ones.

I've been researching this at home (I'm hoping to get one of these soon!) and as far as I can tell, they're more efficient than doing dishes by hand, both timewise and environmentally, but I don't know about efficiency of the small ones vs the large ones.

I do know that you can get a little countertop dishwasher that is Energy Star compliant, which is nice. I haven't bought one yet, though, so I couldn't tell you if I like a particular one. I've just been reading reviews like crazy.

I had a Danby portable dishwasher until I moved to a place with a built-in, and it was fantastic. It cleaned the dishes better than many normal dishwashers I've seen, and you could use the top for additional counter space. It hooks right into your sink -- just make sure you have a "normal" sink that is compatible. Only issue is that it was pretty pricy -- I think I paid close to 400 dollars for it, but if you can find a deal or find it used, I highly recommend. I'm guessing Danby's countertop model is also good, based on the quality of the portable model (DDW1805) that I owned. Here's a link: http://www.danby.com/product/DDW1805W/11

I have a Compact Appliance dishwasher, which I recommend highly. It uses probably 2 to 3 gallons of water per load, certainly less than I would use hand-washing, though I don't know how that compares to larger dishwashers.

(My washer is about 18 months old and working well. The first one I was sent had pump problems, so I had to return it for a free repair/replacement. Compact Appliance also paid for all shipping, all after one brief call to customer service.)

We had this Danby model: http://www.danby.com/product/DDW497W/11

I say "had" because it lasted for six months. The first one we ordered arrived horribly dented, and the second was also dented, but less so and we just took the 10% discount rather than bother with shipping the whole thing again. It didn't clean dishes well at all and almost nothing fit in it, so we ended up doing half our dishes by hand anyway. Finally (after six months, like I said) it stopped working, and I couldn't reach Danby to save my life--I'd be on hold with their help line for up to half an hour no matter when I called and no human in sight. We finally just threw it out and were out the $250. I wouldn't buy anything from Danby again.

Almost all of these break after 1-2 years of use, if you're OK with that then move forth but keep in mind break can mean spilling and endless supply of water all over your apartment (luckily I was home at the time). Also they work great for traditional dishes but a large pot will fill a single load and they are awful with plastic, which includes most of my lunch containers. I just went back to hand washing and supplement with the occasional paper plate.

I have this Kenmore 18 inch portable dishwasher http://www.sears.com/shc/s/p_10153_12605_02214412000P, and it is awesome. My husband (who has dish washing duty most nights) thinks its the greatest thing ever. We're in a rental so we needed a portable. It got clogged once after about a year and a half but Sears sent someone over for free even though it was out of warranty. It's energy star compliant and uses less water than hand washing. We paid $400 for it on sale, which is worth the hours we have recovered.

i recently bought a used portable dishwasher on Craigslist. i don't recommend buying anything you can't adequately test used. i don't know if mine broke on the bumpy ride home or if i bought it broken or what but i wouldn't do that again. i ended up at Sears a couple days ago instead and will soon have a $500 Maytag EnergyStar portable. Sears by us has very good service, free delivery etc.

I recently bought a used portable 18" Frigidaire dishwasher. It hooks up easily to the sink and works well.

Honestly, the best part about it is that it adds useful counter space to my small kitchen. I would definitely recommend it.

Only drawback, very heavy. Thus hard to get up a 4th floor walk-up.

I had a Danby countertop dishwasher. It took up exactly half of the countertop in my NYC kitchen.
I was very happy with it. No problems for 3 years. I only let it go because I moved into a place with a built-in.

I had a horrible experience with a Danby, I should've read the consumer reviews before buying it. I've been told that countertop dishwashers just have more problems in general. If you've got the space, get one of those bigger ones with wheels for carting around.

Thanks everyone! I ended up going with a full-size portable by GE, and I absolutely love it! Just posted a full review and writeup on my blog, if you're in the market for a portable dishwasher, please check it out: http://achefsdaughter.com/2009/09/ge-gsc3500nww-portable-dishwasher-review/

Thanks to the Kitchn for posting my question!

Count me in as yet another super happy Danby countertop dishwasher owner.

I have a Danby 18" portable dishwasher, and I absolutely love it. It cleans great, it's Energy Star rated, it's narrow so it fits into my small kitchen, and it gives me an extra counter. A normal cycle takes around 90 minutes, but I don't mind because I'm not standing in the kitchen washing dishes. I love that it can be built in by removing the side panels, and freestanding, I find it quiet enough.

As far as the efficiency of running a smaller dishwasher vs a full-size, I think you just want to run full loads. I knew with just two people in our household, it would take forever to fill a full-size dishwasher, so we'd either be washing individual items to use or running the dishwasher before it was full. With the 18", we run it 2-4 times a week, depending on how much cooking we do.