I've had a Roomba for a couple years and LOVE it. We have dogs and cats and it does a great job on pet hairs, dust bunnies, dirt, etc. It is not a replacement for vacuuming on carpet, but does a good job freshening up the carpeting, especially for those of us with pets.
It does a wonderful job on laminate and hardwood floors. We just had a 400sq ft new laminate floor put in our kitchen/laundry room/breakfast area and we run it in there every night. Our bedroom is upstairs and the noise isn't enough to bother us. I can hear it running enough to know that we remembered to start it, but not enough that I have a hard time going to sleep.
There are kinks with it and this is about our 3rd one, but the company has the best customer service of any company I've ever come across and we haven't had to ever pay for a replacement, even when we were past the 1 year warranty. If and when it breaks again we'll rebuy without question.
We now have one of the newer ones with the larger bin, more powerful motor, etc. We don't have the self-charging base, but it is an option.
I highly recommend the Roomba, keeping in mind the limitations.