Don't know that you are being 100% accurate here boss. I taught at a busy flight school in that did part 61 and 141 flight training (as well as a large university 141 program). There was no priority one way or the other for scheduling and 61 students were treated just like 141 students and vice versa. Only difference is that the 141 students came in for a couple hours 2 nights a week and the 61s did not. I taught both the 141s and 61s and scheduling was dictated by the student's schedule. Yes, in 141 you have 12 months from the time you start a course to finish it but that is usually not a problem and definitely doesn't mean we told the students when they would fly. In fact, several of the 61s had day jobs and knew when they could fly and would schedule up to a month in advance.

Now, at the 141 university program I taught at (my screen name is a clue) students would select a "launch time" which was theirs for the entire semester until they finished their course. Basically each student "owned" an airplane and their instructor at the same time 3 days a week. If the student or the instructor or the schedule dictated something else, FINE. We would reschedule but the student had first right of refusal for an airplane at their "launch time". If a student wanted to fly more than their scheduled launches that was usually possible (unless we ran out of airplanes). This is a good system for a large flight program because you don't have students and instructors always juggling their schedules, its adds a rhythm to the training and it reduces scheduling conflicts.

So from someone who has trained and taught in both environments, each has its advantages and disadvantages. If you are the type of person who needs some structure and prefers more of a "school" setting, I would recommend 141. If you are a self-directed learner and don't require the structure then 61 should fit you well.

As far as your comment about taking more than a full-time course load and working 50-55 hours a week I think your real concern should be whether or not you have enough time to devote to flight training. If you can't fly at least 3 times a week and spend 2-3 hours a day studying then you are really wasting your time and money. You may want to think about waiting until the summer or another time where you aren't so busy and "blitzing" your PPL. Train 3-5 times a week, study your butt off and knock it out in a 8-10 weeks. It will save you a lot of time and money.