Yes we use the litter kwitter and I think it is a great invention.
We still use the rings on the toilet but there is hardly any litter in it, they now just jump up on to the loo and do what they need to do - only Darwin (the bengal) likes to have a scrape at something.

I would say if you have enough toilets give it a go if you want to, but I would say you could try Mai Tai now rather than wait till she is older as we started Rosie on it when she was tiny and she has been fine and actually trained quicker than the boys.