I am mulling over which way to go for my XLL1200 ; mill my current head (already posted about this) , buy a used one and have it milled as my ski is in deep (22 inch snowfall last weekend) storage ,or shop for R&D or Riva head kit . Caught Osidebills Ebay for the Pro-tec head - What makes these so reasonable compared to the other options ,new they are listed for $250 compared to ~ $500 for the Riva style (domes and girdle kit) . Are the one piece billet heads prone to failure ? to me it seems cost effective and pretty fool proof for the one piece head like the stock unit .