Its been said already but I will reaffirm that - in my opinion - gadgets such as paddles, fins and pull buoys are no substitute for solid technique. If you want to get more oomph on your stroke (i.e. on your catch and pull) then try using fist gloves. I received a pair when I did the workshop back in '08 and they are a great way to see how good your balance and streamline are. Try doing some 25 meter or 50 meter sets with those on and then take them off and swim without them. It will feel like you have dinner plates instead :) Anyway, that's just my opinion.
Swim in the rough water to appreciate the smooth!