Which 15mm wide mini servos do you have the best luck with?
MKS 747 seems to be the gold standard. The ones I've used have been great.
I have a set of Promodeler 355's and they have been good so far. I thought they were the best, but my last conversation with John left me wondering.
I have used Savox's in RC cars with great success, but their airplane versions have not been great - I have a set of sailplane wing servos that didn't last a season and a set of micro servos in an electric 3D job that went bad fast, too. I wonder if their 15mm are any good.
Futaba high end servos seem to be awesome but tend to be ultra expensive.
I use KST in sailplanes and have really good luck with them. But never tried any as big as 15mm.

I'm paranoid that a single servo can cost me an entire airplane.