I've tried 4 systems. The Australian ATR type, don't like them, too much time taken to construct them before use and they go in the corner of tiles so you can't see if the tiles are aligned perfectly, also not very strong, they break of premeturley far too often. I tried both the 2&3mm sizes and also the T type.
The Lash system I found to be too crude and bulky in comparison to similar type systems.
The Ramondi RLS I tried last week for the first time, couldn't wait to try them as so many members use them. They are very well made, good quality, but they do tend to move the adjoining tile and you constantly have to check that all is in line.
The system I've used the most is the Genesis, both versions. In my opinion this design of clamping tiles is much superior because there's no lateral pressure only vertical therefore no moving of adjoining tiles what so ever, a much more accurate way of working plus there's no tile depth limit restricting you and if your working with say a slate tile for example they can still work. My criticism of this system is that it's not quite as well made as the Ramondi system, the teeth on the pliers do wear out after a while and on the smaller top caps you will get small wastage when breaking them out the next day.
I've yet to try the Rubi system, but as it's the same technique as the Genesis system I'm sure it will be an excellent product, therefore for me it would come down to price and availability.
I'll post a pic of a floor I did using the RLS and the Genesis system together to see how the preformed in exactly the same conditions and tiles.