This one seems to do a good job, but I have nothing to compare it too as far as the older model goes.

I turned it on when I left for work this morning and when I came home it was back on it's base ready to go again. It had quite a bit of junk and dog hair in it that would not have gotten picked up yet so that's a plus. I will still use the big vac also but in between uses this is a help.

It leaves tracks on all the carpet and it appears to cover all the floor pretty thoroughly for what that's worth.

The floor mopping one does a great job on the floors but I have to say that it does not recognize where the tile ends and the carpet begins. I will need to get a couple more of the little tower things that tell it where not to go before it is safe to leave unattended. It works well enough that I will get them though.

They aren't perfect yet but they are a big help and the day is coming when they will be a part of every house. I can see how the sensors will be hidden in walls to tell them where they are in the house and you will program them just like you do your sprinklers or DVR. They may even clean themselves.