So Grp n offers a couple of benefits. It gives a better midrange punch that you don’t get with the standard engine, and it also alters the dynamic compression ratio. You do get some improvement in the power up top as well, but I never felt the need to rev mine out - and I’ve got proof for anyone that wishes to watch and make the decision for themselves:
You can see and hear that the engine isn’t being maxed out in the revs, and the shift light under the binnacle also shows it. I guess you have to make the decision for yourselves though really.
I’ve seen results from the various setups and the Grp n always seems to look better on the graphs over the 197 cams. But, there’s no denying that they do give improvements, even more so when the 730/736/738 engine is built up using 197 internals.