Having had an F and a K (231) before my E, (all turbocharged), I have a few observations:
1. Manual gear is easy to get used to and much cheaper to maintain. As long as your shoulder works, it is superior. Not as sexy though. (My E has electric flaps)
2. My E is 10 years older than my F and 15 than my K. There are differences which some people overlook. Lack of sun visors. Older yokes and door handles that break. Steel windscreen tube that messes up the compass. No emergency baggage door unlock. Flying in the yellow arc alot. Fewer autopilot options. Wiring that is ancient and hard to troubleshoot. Vents that don't work the same way. Mooney really did improve the airplane over the years.
3. The K engines usually need a top overhaul about 900 hours. I loved my 231, until I had to pay the bills. Unless you need to fly high (over mountains, weather, or winds) they are a lot more expensive than an F. For me, it wasn't worth the extra money anymore.
Which one is best depends on your mission. You are smart asking lots of questions and getting loads of free advice.
Good luck!