I've recommended those pistons to a few people on the UK Mk3 Forum and so far no problems have been mentioned. As long as the block is bored and honed properly and the pistons matched to the cylinders, new bearings are used and the crank is polished - i dont see any reason why it should fail at all. Granted its a mostly stock build, but with ARP's clamping the head down, 12 to 15psi should be an easily attainable goal and be reliable at the same time.