i found that folders don't last as long tho, so unless you have a need to fold em up for travel spares, just go for rigid.
i once had a folder roll off my rim while i was cycling. i noticed it and thought "o my tyre must be flat" and then BANG!!! my inner tube blew. the tyre had rolled off which caused my inner to blow and go flat. after i changed it, it was a slow cautious ride to the nearest shop (10 mile away!) where they told me that it the edge had weakened, probably because it was a folder (didn't realise, it came with the bike). always had rigid since. the other folder which came with the bike had previously failed also... the wall of the tyre gave way which made the tyre distorted and gave it a weird kink. i only noticed because the tyres had a stripe down the middle which made it obvious. that probably would have caused me a problem while riding.