the difference is that edges on the 0607 PCs is a 1.7mm edge, while the rest of the Armada line (and this year's PCs) has a 2.3mm edge - it's just not as thick and won't hold up as well to rail impact... the bases are more porous too, so you need to make sure they get waxed regularly or they'll dry out quickly... you can definitely hit rails with them, but if there's rail-related damage and you go to warranty them, they won't be accepted....