I have trained and instructed at both 141 and 61.
141 training is too structured in many cases, and people get stuck repeating things they've already mastered. Or if they don't they master on schedule they have to keep repeating it at additional cost...in 61 I'd often move on to something the student was better at to allow him to build more experience and confidence before re-attacking the problem area.
Also in 141 you can finish with less hours, so naturally the 141 schools charge more for the privilege...so you pay more and graduate with less flight time! Is it just me or does anyone else see the problem with that?
IMO 141 is only good for military VA benefits. Even if you're attending an aviation university you can do your training part 61, save money, and get more flight time. The 1000/1250 hour restricted ATP might justify doing a 141 program, but you'd have to do some math on that (your time vs. your money).