BBC valvesprings/beehive

If a HR cams are really only good to 6000 RPMs, what benefit would I see from using the beehives which are supposed to allow higher rpms? From all the tests I have seen/read, there seems to be anywhere from 10-20hp gains from installing beehives. The majority of the gains seem to be at 5500+. I can pull 6000 now no problem, but my engine makes peak power at 5250. Is there any benefit to reving it higher?

I'm debating if having the pockets of my heads deepened for these springs is worth it, along w/the fact now there's only one spring. Shifting at 5200 to 5500 would make me think that 'hives wouldn't be that much more effective than what I have now. May be just as effective to get a better set of dual springs to replace what I have (if even thats worth it).