I don't fly as much now as I used to (now - about 30,000-50,000 miles per year; previously about 60,000-100,000 miles per year). I have been working in international regulatory affairs (sometimes on the public side, sometimes on the private) for some time. The travel experience has varied, depending on the post. In my best job (from a fun travel perspective), I took about a 4-8 day trip once every 6 weeks, about 3/4 to Europe or Asia in J (carrier of my choice) and 1/4 in North America (economy, but usually no more than a 3 hour flight). The hotels were 3.5-4* (rarely 5*) and I got time to sightsee, and could add a day or a week's holiday to the trip pretty much whenever I wanted to. The meeting organizers also typically organized a couple of social events for us during our trip, so it wasn't all work.

The worst was working for an international public sector organization. More Y class flights (anything less than 8 hours) and often on scary national airlines from developing countries and with a requirement to stay in 3* hotels only. On the plus side, the travel was more exotic - I certainly went to some places I never would have thought of going to on my own dime (e.g., Tbilisi, Georgia). And I did once have a day (personal record for me) of standing on the soil (not just transiting in an airport) in 4 countries in one day.

One thing I'm glad I've never had to do is the domestic road warrior routine - e.g., weekly trips to the middle of nowhere via a seat at the back of the plane.