[Dwarf99]

Social Engineering goes into great detail on what each reaction band does. Personally, just like Stoddard said, I'd be ok if you kept the original reaction bands. But I'd be ok if you expanded the upper end to include the additional 4 point categories. That way you could say... play a nymph with their +10, and get +4 from those affected by personal talents for a maximum of 32. You still might not end up being as granular as needed to fully benefit from a maximum roll of 32, but keeping 4 point reaction bands pretty much leaves your average Joe untouched.