(note: long response post warning, lots of scrambled thoughts hopefully not to hard on a readers patience. My biased effort with its limitations at seeing the context )
I agree we will see a difference, but the positive momentum thing isn't worth the other losses imo.
I want over powered cars that demand and get the most rapid deacceleration into and acceleration off the corners. I realize losing tenths of a second is next impossible to see with the naked eye and I don't care about that point. But the deacceleration/ acceleration ratio is very apparent and it is something to fight for keeping.
And loosing that basic crude beauty would be a true loss. It does take skill to keep the momentum but it isn't as interesting as watching more overpowered cars that are struggling to work their way through the corners. I also think it is a more diverse type of racing with more strategic approaches than just maintaining momentum.
The more overpowered cars will have more trying to out dive a driver into the corner, and others who are quicker off the corners. Momentum racing is more unforgiving and conforming you can't try as many lines because getting out of sequence is to just costly, hence you are more regulated and less risk taking. Track position will matter more than ever.
In simple terms they will be more bland spec cars, than a pure beastly race car. You can even momentum drive a 1973 Pinto or Vega because you need more speed down the Hill to go up the next Hill. While something that has too much entry and exit speed is more pure as a race car.
I believe the new rules are just more band aids for 1.5mile cookie cutters, Michigan and California. An effort to turn them into mini RP tracks. It will make for more pack racing, and it might help those tracks. But I would not trade any of that for the lost power throughout the schedule. The cars will be less beastly at places like Martinsville, the road courses, Pocono etc, and I do think less power hurts these tracks.
Technology is a Heaven/Hell thing in racing. The raw brutal power and it's beauty is the allure. The thing gets our blood going, at least it should be in my mind, otherwise I have totally missed something huge. But we can no longer have unadulterated power Otherwise Indy Cars would be 250 + down the Indy straights, maybe the corners too and still obliterating drivers in the style of the 60's and 70's. Cup cars would probably do 240 at the current RP tracks and a flyer(s) would have already produced a Lemans type of tragedy.
Wisdom had to sadly deal with those power and speed issues, but that almost thankless task was a requirement not some pointless change. We now have the safest car we have ever had and I don't think the HP reduction in this case has a thing to do with that concern. Without that concern I just cannot see the value, and something wonderful is needlessly getting sacrificed.
I hope I am proven wrong, but it is hard to know, Nascar's muzzling system will force us to wait and see, and the comments from those in the loop have their limitations. We will just have to hope for the best, there are a lot variables and this grand experiment is here to play out like it or not. With all the variables it is probably a 50/50 thing.
The only sure thing is that racing is great with a lot of elusive qualities, and that we as fans will continue to nitpick.
If this does work, I still have plenty of ammo to keep the hate on Brian.