Here's input from someone (not me) who's tried the TI66, and who can compare it to the Masterpiuma:
"oh, for gods sake dont get the t1-66s. as i said it s the best rubi to date but, the build quality isnt as good as the monti and the cut and the ease of cut just doesnt compare."
'Nuff said
Mind you, I don't think Rubi make bad cutters (in fact, I kind of liked the TS-30 for small tiles), but from the ones I've tried, I'd say there are better ways to spend your tool budget.