I put a MBT14B4 on mine early this year as well. i cant say how well it will last a winters use but it kicks out a lot more starting punch than anything i have used before.
i tend to get through a new battery each year or just over, due to the way my bike is used (used a lot but then could be parked up for a week or 2)
this one fits fine (not to sure i like the conections but they have worked perfectly so far)
gives a lot more punch on starter, the motor turns over faster and starts instantly.
we shall see how it is over the winter