The V2 doesn't have that annoying warm up period at start up, it just starts searching for satellites straight away.
The V2 is meant to be more stable
The V2 has a better PMU allowing you to expand it's capabilities eg BTU, GS, IOSD
Classic "toilet bowl" action generally caused by a flawed compass calibration or gains set much too high. Work on the compass calibration first.
Also verify the GPS and EMU is facing the correct direction (towards front of copter) and that X-Y-Z data for GPS has been accurately entered in the Assistant.