Of all the comments here what stands out the best is that there is no general answer. The size of the lake or river, the type of fishing you do, regulations controlling the type and size of the motors, the style and weight of the boat loaded for fishing. All this must be considered before any motor size can be discussed or criticized. The lakes I fish on are small by many standards 80sq-100sq miles. I mostly troll for White perch, electric only motors and signed affidavit not to place the boat in any other bodies of water, I have a 1448 Tracker Grizzly. I have 3 80lb thrust motors, 2 Minn Kota Traxxis on the back and an Ulterra on the front. 6 120 amp hour AGM batteries 2 for each motor. The reason for this set up is to be able to get to the extremes of the lake and BACK without the fear of a motor failure. If I lose a motor due to some malfunction any one of the motors by itself will get me back to the ramp. The Ulterra allows me to program a trolling route and will keep a constant speed regardless of the wind in most cases. The Traxxiss running at 50% on still water get 3mph and give me 2 hours of run time without depleting the batteries past 50%. I use the Ulterra to steer with while traveling just turn it on long enough to make course corrections. This set up works perfectly for me and was within my budget. The improvements I will make when money allows is to replace the Traxxis with a pair of Torqeedo electric outboards and Lithium Ion batteries.