Its a no brainer that the 2005 pilot 5.2 is the better bike AND cheaper (full ultegra and lighter wheels). Be advised the new 105 10 spd group is not better than the ultegra 10 spd group, its still a component group down. Its the older ultegra 9 that the new 105 10 is being compared to, and even them I am not sure its as good. If I were me its clear I would go with the 2005 pilot 5.2, its still brand new, and better equipped. In my experience, your LBS will appreciate your continued business for service, parts, etc. Perhaps the first time you bring it in for service, you could comment that your dad picked it up as new old stock for you as a gift, so then they would understand better him buying it from his bike shop. They would also understand that its more bike, afterall these guys are cyclists too.