We have two "samples" which our merch team use. Given by the rep trying to get us to buy them.
We have a Pro65 and a Tech125. Although the designs and principles of the machine are comparable to Rubi. TX1200 vs Tech125, on testing, the Bellota cut some real nasty 60x60 porcelain that for some reason the Rubi really struggled with but managed eventually.
The Pro65 and the TS60+ both cut fairly equal on ceramic tiles, but even with being what seemed to be a slightly more solid machine than the TS, Bellota seemed to struggle with some porcelain that the TS did with no effort. After that we decided not to take Bellota's into stock and stick with Rubi. My opinion is that overall, the Bellotta just edges it, but not enough to switch tool supplier.
All the tiles used, I also tested with my Montolit 63..... It was no contest. Monti all day long! I will get round to trying a Sigma but the Monti see's me ok for the odd job I do.
Now what you need is an army of Sigma owners to come running in with grenades and chain guns to attack the handful of Rubi, Bellota and Monti owners defending their cutters with nothing but pitchforks!
It'll be like watching the Predator vs Sooty, or the Russian army invading Liechtenstein.