i think its like anything they will work longer,harder as the season progresses when they are getting fitter,but imo 4,5 rotated should still work fine the next day
when your out and you get the odd rabbit etc running towards the lamp a brighter lamp will defintly dazzle it more than a less powerful light but apart from that cant see any difference myself ,
good stuff theres some amount of rabbits come of there lately well done the dogs and owners, never done them sort of numbers myself but can imagine its fecking hard work carrying and moving them about up down that ground