I have the Krups model, and while it works fine and gets the job done I have a couple issues with it.
First, the beans don't always evenly flow down to the grinding blade/burr, so I often have to stand there and give it a nudge or shake to get it to keep on grinding away, as opposed to just spinning freely really damn fast and loud.
Second, the ground coffee then seems to gain a static charge or something, because when I remove the container the grounds always seem to jump out onto my hand or all over the kitchen counter. It's just an annoying little mess, and it seems that every day after using it I find myself having to clean up a big mess on the counter.
I'm not sure if anyone else has ever noticed this, or if it's a problem inherent to all burr grinders.