Starboard phantom queries

Hi all

Wonderered if anybody could help

I sail mainly a kona on inland waters. Looking to give more serious raceboarding a go. I'm a super heavyweight (110kg) and have loved sailing the kona but it's not the earliest planer. I already have a large early planing shortboard but given that i want to now trade up my kona for a raceboard, can anyone help me with the following 2 questions:

1. Between last seasons phantom 380 and this seasons 377 is there any discernible difference in early planing? I am concerned about paying more $$££ for a narrower board even if i am faintly seduced by the claims for the new batwing design?

2. Never used a sliding mast track. Is this north pin by design or will my kit which uses odd proprietary systems of UJ still work? - neil pryde mxt and the north shox system, i'm thinking of.

Thanks for any help

Martin