I prefer the thick leather of the Thea line to the saffiano Robinson items. That said, I got a pebbled leather double zip Robinson tote that the leather is fabulous. That is such a personal preference that I doubt it is much help to you. Sorry! I don't think you can go wrong with either of them.
I prefer the Thea, just bought it actually... I like the leather strap better than the chain, it just feels less bulky and more appropriate for day use, which is my personal preference.
I find the Saffiano robinson items verryyy sturdy. I tend to throw my things around with little care and don't find myself worrying about scratching them!