The emphasis in peoples thinking on this subject usually involves finding the path that requires the least flight time. They wish to shave off a few hours here or there to save some money. But this is not a very good strategy for a couple of reasons. One it presupposes that you are talented enough not to need those extra hours which is something you do not know until your actual checkrides are passed. Second for pilots wishing to go on to a professional flying career, they will need far more hours anyway; as many as four times more than a wet ticket commercial usually has. Saving a few hours on flight training is of no particular advantage for aspiring pros and as King said you probably need them anyway for better skill development. To save money in flight training there are definitely some things one should do but choosing Part 61 versus 141 based on the hours requirements is not really one of them.