I've used an LFX14A2-BS12 battery on my 2007 CBR600RR a little over a year, since February 2011. Sad to say I mostly only ride very short trips in the city, with a lot of idling at stop lights, and low rpm riding, so the battery isn't regularly getting charged by the bike at peak alternator output. When it's cold I plug in a heated vest with a thermostat. It never dipped much below freezing in the last year, but still, fairly tough use for a battery. Only about 2,100 miles, and a lot of sitting in the garage.
I've never needed to attach a charger, and the bike always jumps to life, thanks to the higher voltage delivered during cranking. On a sport bike with barely enough room to store a pack of gum, the extra room freed up by the tiny battery is useful.
And of course weight, weight, weight. (Posted on 4/22/12)