I have decided to change my deore levers that I am using with the deore mechanical brakes for Avid levers (after some search on the internet it seems that Avids will improve the deore discs - do you agree?). So, I am between 2 Avid SD7 and Avid SD5. Are Avid SD7 levers better than the SD5? At chainreaction SD5 are more expensive. I thought SD7 are the upgrade of SD5. Thanks.