I'll weigh in on the "harder" debate with my experience with coaches who had coached at both levels. Specifically one guy who was a QB coach/OC in the Big 12, ACC, and several mid-majors + WR coach in the NFL for a few years, and another who was a mid-major OL/TE coach + position-less offensive assistant in the NFL.
They both were pretty adamant that they considered the NFL to be the cushier job. I'm not sure they ever really said that it's an "easier" job, because the hours are the hours and the stress is the stress, but what they would really harp on is how much extracurricular work you need to do at the college level. Not just recruiting, which is a ##### but was more of an offseason role for both of these guys (they were not our recruiting coordinators or anything like that), but the other stuff.
When you're coaching in the NFL, your job is football gameplanning. You go to work, you gameplan, you watch film, you have meetings, you have practice, you go home. The players on your team already know how to know how to play their positions. They're adults. There are veterans on the team who keep the younger players in line. You don't need to babysit your players - they are grown men, professionals.
When you're coaching in college, you have a drastically different role. Many of your players are very raw for their position. You need to focus less on gameplanning against your specific opponent and more on fundamentals, actual on-field coaching. But more than that, you essentially become a surrogate father-figure for your players. The veterans on your team are like 21 years old and aren't much more emotionally mature than your 18 year old freshmen. Many players come from questionable home situations, and it's their first time away from home. You, their position coach, are responsible for making sure he's going to class. For making sure his homework is getting done. That he's not out partying every night. That he's eating right and taking care of himself. That he's not depressed or having emotional problems being 2000 miles from home. You essentially become a surrogate father to the ~10 players in your position group for 4 years. You are the role model. Oh, but you guys went 3-9 last year because you had to deal with all this other off the field ####? Sorry, you're fired.