Which pixhawk to buy?

Hi,
I’m new to the sub/boat field, but I used to build drones, starting with the APM pre-pixhawk 3dr autopilot and the built a few copters based on pixhawk 1. But that was some time ago and now I’m moving in to the wet side of the world and will build:

  • an autonomous surface vehicle (for shallow water mapping)
  • ROV with tether (for fun, 300m depth)
  • AUV/Glider (1000m depth)

A lot has happen on the autopilot side, should i still try to get the pixhawk2? What about more modern versions? What about the Cube?

I am also curious about this question. I’m about to convert our Seafloor Systems r/c sonar boat for semi-autonomous operation. It’s difficult to know the pros and cons of each autopilot module/platform up front.

I’d hate to make a poor hardware decision, then get stuck with crappy control software down the line, you know?

This is the only decent comparison of the options that I’ve found so far…