Recommendations for next iteration of Arduino

Micro OTG B would be best if looking to converge onto a connector type. This connector is the becoming standard for mobiles. The main difference between the micro and mini is for lowest profile, i.e. as needed in mobiles.

Regarding the comment about reliability, its my experience that the SMT connectors are unreliable where they solder to the PCB.
This is especially the case with USB seeing as they are unplugged and plugged in again, and again, and again!

So, my top pick would be a Through hole Micro (less preferably Mini) OTG B connector.