Chad / Dave / Keith have lots of experience and provide good info. A couple of additional points are that it's a bit easier to cool inrunners and the planetary gearboxes are very durable (kinda popular in automatic trasmissions also).

The cooling thing was a big concern when I chose the inrunner, I fly a lot in temps at +90F and have had excellent service from both the Hacker Comp & Neu motors. I will point out that the Hacker Comp fans were no problem until an "improvement" was made to improve efficiency by adding a phenolic disc to the fan. These discs do fail and can tear up other stuff - I don't use them. (Simple to remove.)

I originally had concerns about gearbox strength, but not to worry. A 30 min lube job every 100 to 150 flights with a good polyurea grease and all is good.

So it gets down to occasional bearing replacement, in either type motor, after lots of use. Isn't E power great!