The old 61 v. 141 debate
I trained under Part 61 and most of my aviation work experience was in 141 schools, so I feel I've seen it from both sides of the desk.
My Part 61 experience might be different than both because I trained over a period of years and I used instructors who owned their own airplanes and were doing it as a sideline. Also, I had not set out originally to be a professional pilot, so dragging out my training wasn't a problem except that it wasn't conducive to a quality training experience.
Having said all that, while Part 61 provides a great deal of flexibility and far less formality, there is something to be said about 141's discipline, organization and standardization. 141 is school, and all that school implies. You have to prepare for each training activity thoroughly and you train on a regular schedule. That builds momentum and continuity, which will help you learn faster and better. You have to meet certain standards for each phase of training before moving on to the next phase. That helps assure that any weaknesses in your training which could impact your flying have been addressed. The standardization helps you prepare for training for the flying jobs you really want. Training for those jobs is highly standardized and probably stricter than even the toughest 141 school. Better to get a taste of it during your formative period than later when your habit patterns are ingrained.
I agree with FmrFreightDog about doing plenty of research. I think my best reference for 141 schools is me. My 141 students were further ahead than I was at similar points in training.