It depends on WHICH Tuftex-brand product you've bought. If it is the pvc (may just say 'vinyl') or 'seacoaster' panels, which are the cheaper ones, then it will not hold up well over time (in particular, hail will shatter it and after a coupla years I wouldn't expect it to withstand much wind). If OTOH you bought the more-expensive polycarbonate version, it's really good stuff.
The main thing is you need to GET THE INSTALLATION INSTRUCTIONS AND FOLLOW THEM EXACTLY, no foolin'. If the store where you bought the panels didn't have installation pamphlets, you should be able to google a .pdf of it up online. (You can for other mfr's, I haven't personally tried looking for Tuftex's) Seriously, you need to follow the instructions for how to support it and how much unsupported overhang is too much and how to attach it and what size to predrill the holes and all that. It will work real well if you install it right; it will work real BADLY if you don't.
As far as flimsy, as long as you've got the (more-expensive) polycarbonate panels, they're really quite tough. The only thing I'm not sure about is if a raccoon started actually *chewing on* the edges. If this concerns you, put a layer of wire mesh underneath. I have yet to hear of anyone ACTUALLY having problems with raccoons gnawing apart the plastic though so my suspicion is that it's not a real big issue to say the least.
Good luck, have fun,
Pat