> For instance my own experience was quite positive.

As was mine, despite not completing it. However, I don't think I'd want to deal with the negatives at an older age.[1] To put it another way, if you're older and want admission to grad school so you can learn a lot, and are not too particular about actually completing the PhD, then you probably will enjoy the experience and can ignore my previous comment.

Also, if you have the resources, a second BS or MS can be fun. I knew at least two students who were in their 60's pursuing a second BS (one of them was pursuing both a BS in math and physics, with little background in them). They both enjoyed the experience and were quite content. However, a PhD is quite different from that.

> You choose a professor based on how their research program appeals to you, and there is often room for compromise.

If you've had prior research experience, this advice may work. If you haven't, then you will likely be wrong about whether a particular professor's research program appeals to you - and you may not realize this until you've been in the program for a few years.

> I think that in general, there aren't really that many top rungs for professors to grasp for, and most are comfortable having a relatively stable career and focusing on the educational aspect of their research programs. I live in the shadow of a great university, and some of my relatives are professors, and this pretty much describes their attitudes.

Having spent time at both a mediocre and a top school, what you describe was more in line with what I saw at the mediocre school, and not at all like the top school. Most of the professors in the engineering departments were always trying to climb the rung, and competing with everyone to do it. Things got very petty. My advisor, who was already a Fellow of 3 large professional bodies (IEEE, physics (AIP? I forget), etc), was still quite competitive, extremely protective of his research, upset if a paper got rejected and would try hard to find out who the referees were, etc.

I remember wondering why he was so invested in all of this. He was fairly old, had achieved a lot, and what more could he achieve?[2]

He was not an outlier there. Even the more laid back professors would eventually exhibit some of this behavior because not doing so would demean them in the eyes of their peers (and yes, one of the benefits of academia and tenure is supposed to be that you're relatively immune from this, and yet...).

Now at the mediocre university, it was more like you described. In fact, not many professors even had PhD students. There it was more about the research and not the career.

And yet, in my last few visits to the department (again, engineering), the professors told me that even there the culture was shifting to being more career focused. The pressure to get funding was much more, etc. The common sentiment from people who had joined the department in the 80's through the 90's was "The level of work I had to do to get tenure (number of papers, funding, etc) will not get anyone tenure now in this department."

I see you were in physics, and the experience there can be different. In some universities it is less funding driven than in engineering, and there probably are fewer rungs to climb (or perhaps they don't value those rungs as much). In the top university I went to, the physics department was actually in the college of engineering, so the pressure for funding, publishing, etc was similar to engineering.

> I sympathize with not finishing, and would never hold it against anybody. One thing finishing did for me was force me to keep going until my project was really ready to go out the door.

For me, a lot of the problem was that I sincerely doubt anyone will ever find a way to test my results. Unfortunately, a lot of theoretical/computational engineering/physics is that way. Did I really want to become an expert in something that no one will ever prove/disprove? It wasn't just my research, but much of my discipline, and a lot of why papers would get accepted/rejected had to do with groupthink.[3] It really felt like I was doing literature where subjective opinion matters so much. I remember asking some of my peers if they even believed their research, and for many it was a strange question: They were in the business of publishing papers and getting research/academic jobs, not seeking the truth. If it's publishable, it's good!

Ultimately, I picked the wrong area to do research in. Also, one of my undergrad professors told me it was a hot, young discipline. He was right in some ways but was mostly wrong. It was very mature by the time I entered grad school, and that usually means a lot more time (years) studying to get to the state of art before you can make a meaningful contribution. As a general rule, I tell people going for PhDs to find a discipline that is not mature - it'll be easier to make meaningful contributions that way.

[1] Arguably, I probably did not want to put up with it at my younger age, and it probably contributed to my decision to quit, but it would have been one of the minor factors in that decision.

[2] And several years later, I know - there were lots more rungs on that ladder. There always are, until you become a president of a university or the head of the NSF or something.

[3] Yes - they did care about your formalism, techniques, novelty of ideas, etc. But there were far too many subjective ways to reject a paper as not being interesting enough to be published in this journal, etc.