they are coming out with a new gerneration, with stronger terminals. i know this cause my friend and i called and spoke with them about the terminal design and how it could be better. they agreed and now are coming out with a new terminal.
other than that, the case the quality the price you can go wrong.
i used the 12amp one on a 750 gsxr. and a stock 1000. i was going to try it on a zx14 but i couldnt get my hands on the bike. they act just like any other lithium ion they seem week at first then as you crank they warm up and work fine.
i guess the one bigger size the 14 amp would be sufficient for bigger motors, but i dont no how theyd act on strokers. although using 2 12 amp batteries, is still lighter than one stock battery by a few pounds.