Around my area, the B4 is the overwhelming choice of buggy... and the LRP Sphere Comp is the overwhelming speedo of choice.
By far over Novak. Most guys here run a 7.5 in the B4... Reedy, Vector, Orion, or Novak. I'm still running my old Reedy 2 star (7.5)
A lot of stock racers do run Novaks but most of the mod guys run LRP.
BTW, the Tekin systems should be really nice... and the Mambas DO NOT have a cogging problem. Any cogging problems have been from the stock connectors. Cut them off or use a different connnector and there are zero issues. The system does not cog, period.