I used Rubi cutters for over 20 yrs... I was sent a Sigma to use after much debate on here and i now use Sigma.... much better cutters all day long IMO..
I totally agree with TF Ed , I went 700 and 1200 as covers all bases. I fix a lot of Porcelanosa and the 1200 has come in most handy on a quite a few occasions.
I have a TX900N and the reason I purchased this over the 700 is because it can cut a 600x600 diagonally whereas the 700 can only cut a 500x500 diagonally. That and the fact that its only a few notes more! Wouldnt be without it (have to say I havent tried Sigma yet though)