Best on-camera flash unit for X2D

[Gethyn]

Can anyone recommend a good on-camera flash unit for the X2D.  I have experience with Pentax TTL units, but have no experience with Hasselblad.  Thanks for the help.

[Ralf]

What harmonizes well is the Swedish way with Profoto, e.g. the A10 with Nikon shoe.  Alternatively, it could also be controlled wirelessly TTL with a Profoto trigger for Nikon (Air Remote, connect, connect pro).

[ymc226]

I just received a Profoto Connect Pro (for Nikon) and some A2 flashes.  The whole system was very easy to set up and works well, TTL and manual.  Much easier and intuitive than the Leica remote and flashes which are rebranded. 

[Conner999]

The X series are Nikon TTL compatible - BUT all evidence indicates that the ONLY products that will allow TTL are Profoto Nikon-compatible radios / speedlights and specific Nikon units. Nikon compatible products from 3rd party vendors (aside from Profoto) such as Godox, etc., do not work - in TTL. 

Full manual can be achieved with any radio/speedlight.