Hi Simon
Never used LiPo batteries are did not like the risk while charging plus the checking of discharge level!
Went straight from NiMh to LiFePO4. I have found that 1000mah battery gives me between 2 to 3 hours sailing in anything except top end of rig sailing conditions. For the sake of peace of mind when racing I usually swap the battery out at 2 hours. Did contemplate obtaining a 1600mah Life to ensure a mornings sailing without concerns.
I am either using a RMG or Hitech monster power arm winch and it does not appear to make any difference to duty cycle. Not had any issues with winch performance (speed or power).
Happy with my choice.
Regards Eric