The Cyclecat one claims to protect the posts in the event that the right side hits the ground and the STM one comes with covers to hide the manky looking springs. Go for the DP if it's cheaper...
about £145 Lee. That's the X factor as to whether I decide to start bringing them over. They do covers to. They are bomb proof!! Minimum 4mm thick everywhere. The REAL trick parts are billet water pumps. 10% flow/cooling improvement and also act as a "protector" for the lhs cover should the bike go down.
Here's one of the covers fitted to the bike with the pressure plate to. I haven't seen a more solid setup from anyone. If the clutch got damaged with those fitted, I guess the rest of the bike would be in a pretty dire state...........