This tile cutter does the job. It just takes a little bit of getting used to. I broke the first tile (and it was thick and strong) by applying too much pressure. You need to take your time and the tile will cut.
I am working with thick and strong tiles and these Nippers are doing the job. If you are like me and you do not do this sort of work regularly beware. Regular use can cause finger blisters, so protect your "nipping hand" fingers