When I first bought this machine I was really excited. I owned the Bialetti stovetop version, which is very popular in Italy.
After TWO months of using this, my machine began to get moldy at the very bottom and the top. Basically, it started to oxidize. I hand wash this machine along with my stovetop, so I was following the directions without any issues. I finally called Bialetti and they suggested using baking soda with water, and then vinegar. Nothing helped and it started to smell.
I was told to send it back to them. After wasting $10 shipping it to CA, the lady told me that I used a dishwasher and therefore was not qualified under warranty. I live in an old townhouse apartment, with no dishwasher. She then started to say that they don't cover oxidization. Buyer beware, I've only owned this for a few months and basically the warranty is useless! Aluminum + water + time = bound to happen to any machine.
Pros: Quick cappuccino, cheaper than some other versions, small, easier once you get the hang of it.
Cons: Hard to disassemble to wash (you're supposed to do it immediately to prevent oxidation, but that's hard considering the bottom is hot). It spills coffee if you don't assemble it correctly. You are supposed to use WATER ONLY. No soap. According to many reviews and Williams Sonoma representatives (who also sells this brand), the inside does eventually get black and can smell, so lots of maintenance required.
My advice is to get a milk frother. This machine seams cheaper than a cappuccino machine, but in reality you're throwing your money away.