I've finally bitten the bullet and bought a robot hoover/mop. Thought I'd be blown away, but I'm not as yet.
This is mainly because I have an old house with lots of nooks and crannies, so I'll still have to do all those awkward spots etc. Anyway, I used the mop and because it only has water in, it's left the floor all streaky. I'm guessing I should have given it a thorough scrub first, then just use it to maintain the cleaning iyswim. It's worked fine on the wood and vinyl floors (mainly because you can't see the streaks!)
So what I'm after is something that will leave my floor clean and shiny - haven't had tiled floors for long so really don't know what's best.