It's too subjective an issue to produce a guide.
Reviews and personal recommendations are the only way.
Of course, having a go at trade events is the best way to have a test-ride.
My advice is this:
1) for newbies / diy and people used to Rubi cutters - if the tiles are less than 600mm - get Rubi.
2) for anything over 600mm I would only EVER consider Sigma.
3) after using a Sigma for anything over 600mm, sell your Rubi cutters and buy more Sigma cutters.
4) Enjoy!