I won't say which ones I've had negative experiences with, and there are a few. I will say I've used the Keurig B60 and N70 and had no problems. The things I like best about pod coffee maker versus regular drip machines are: convenience, easy clean up, many flavors to choose from (without a large investment in different types of coffee), makes one cup quickly and easily (which is great when there are more than one person using the machine). The Keurig makers I mention have over 60 differenct coffees and teas to choose from, which was a big hit in our house.

There are pros and cons to these fairly new types of coffee makers.
Pods are pre-packed units of ground coffee that are designed to drip right into specially designed coffee makers for ease, convenience and easier clean up. So they are basically the same thing as using ground coffee, just in a different format. Pro are that they are easy to use, convenient and give you a consistent tasting cup of coffee each time. Cons are that they pods are more expensive per cup then regular ground coffee and you are not able to make it stronger or weaker, if that is what you prefer. So it is really a personal choice once you weigh some of the pros and cons.