I know the feeling, I lost the small plastic window covering the gear indicator on the rear shifter on the MTB. Quite insignificant but I did the route three time that and the following day looking for it before giving up. Looks like it's missing a tooth when smiling
The new bike so far is pretty awesome, I didn't expect it to be so comfortable considering lack of suspension, thin hard tyres and narrow saddle but maybe is because I ride exclusevly on the road now. This is probably part of the reason for the massive time / avg. speed increase on the routes that I had some data from the MTB to compare with.
Last weekend I visited a friend in a nearby town, took me 35.5 minutes on the MTB with avg. speed of 18.6km/h on a combination of roads, cycle paths and pavements. Yesterday I managed the exact same route in 25minutes with an avg. speed of 25.7 km/h by sticking to roads only and the road bike. Estimated callorie output was simmilar suggesting that I must have pushed the same, although the hills seemed to have leveled up a little his week.
The LBS keeps impressing me, they already know my name as I visited them again enquiring for some pedals which unfortunatelly they didn't have in stock. They didn't pushed me to buy an alternative model, but offered a free set of toe clips (which I'm verry used to riding with) and sugested to spend some more time with the bike before fully comiting to SPDs. Aparently I also have some credit points with them from purchasing the bike so I got some more freebies like a valve adapter and a bottle and cage without having to reach for my wallet. It's little things like these that make a big difference and I fully understand now why people support their LBS so much.