The OP indicated quite clearly that he/she knows little about bikes, parts etc, and asked ? re. tune-ups etc. if bike purchased from LBS (local bike shop). If the person buys a bike off Craigslist, that (relationship with bike shop, a year's service included in purchase, etc.) is not in play. Hence Wanderer's (good) advice: if all that is a non-issue, in his (Wanderer's) view the Sirrus is (all else being equal) a better buy. If learning about bikes/service is an issue, then go with the Trek (new, from a shop). Views on the relative quality of the two bikes/brands may differ, but if the OP is a genuine 'newbie', it's very good advice.