Thanks Disco, well written. Very good point about the cam ramp rates which are overlooked when comparing duration.
The compression isnt drastically changed running the neo head vs rb30, it is bumped up a bit which is preferable in my instance.
From research it seems the RB30 heads are 50 cc and neo heads are 50-53. Worst case 50cc would bump comp on rb30e bottom end to 9.7:1
I will be selecting a gasket thickness to give preferably 9.5:1 comp, after having head welded and skimmed, then measuring chamber volume. I am not after max power, Just a really nice tourqey combo for daily use.