Any opinions on the current version of the Litter Robot?

My mom is 80, and she just can't handle her cats' litterbox much longer, so I'm thinking of getting a Litter Robot for her. It's a huge investment for me right now, but of course if it really does work the way they say it does, it will be well worth it.

I know the product has gone through several redesigns, so I especially wonder whether there are any problems with its current incarnation. Has anyone bought a Litter Robot recently?

Thank you for your help in making this expensive decision!