Any preferences guys and gals? Price difference is negligible, maybe $5 on ebay, and about $12 retail. For those that run Chorus cassettes with Record or Super Record gruppos, do you also pick Chorus chains? I recently bought a 2010 R11 gruppo and ordered a Chorus cassette separately but still need the chain. Question I have is does Record and Chorus cassettes/chains wear differently and so is it better to stick with the same models? Thanks all.