I have owned a 600A Aerostar for 7 years, operated it in both passenger charter and occasional freight. I also had a 310R doing the same jobs. Would have to say that the Aerostar wins hands down in despatch reliability and maintenance costs compared with the 310R. Over the years the 600 was great, the engines Lycoming IO-540s (2000 hour tbo) went full life without even a cylinder off, 310s (continental) always cracking cylinders!
The aerostar doesnt have the payload capability of the 310R in terms of weight or volume, but for the 3 - 4 passenger market (typical demand) they are great.
The later models 601 602 etc with the turbos, pressurisation systems wont give such good operating costs so due to the complexity etc.
Stick with the 600 or go 310 or baron.
Finally they are great fun to fly and they look sexy (if that's possible in an aircraft)
If you ever need someone to fly one - call me!!!!.
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