Rackbot - what do experienced guys think about this

Sorry gents, I’m opening this new topic as I searched “rackbot” and had zero results.
I refere to following product, have no idea about final prices:

http://www.indiegogo.com/rackbot

Looking for opinions, I’ll maybe start to work on a glass cleaner robot (just for fun) and would be looking for a kind of “plug and play” modular thing. Being first project would you suggest something else?
Ciao, Paolo

paopaolo:
Looking for opinions, I'll maybe start to work on a glass cleaner robot (just for fun) and would be looking for a kind of "plug and play" modular thing.

Paolo
A glass cleaner robot needs to go up and down. In my opinion wheels positioned opposite to each other are not the way to go.
Best regards
Jantje

Ups Yeah, good point!
I didn't mention that is for a roof window, roof angle is only 13 degrees.

Anyway the system may be modified as needed, but I intended the question in a more generic prospective:
Is there anybody who tried those prepacked-modular robots? Is it wort or would you start your new automated system from zero?

Interesting and inexpensive bot.