Personally I don't find any difference from one subspecies to the next where Bloods are concerned. It's much more about the individual snake's disposition, and how one approaches it.
I've read for years that
brongs are more difficult than
breits, and that
breits are more difficult than
curtus, but I don't see that myself. I've also been reading for years that size is relative to subspecies and that it's the same order as above from largest to smallest (
brong ->
breit ->
curtus), but I can tell you that I've seen 7 footers of each and that I firmly believe size is more about lineage than it is relative to subspecies.
Of course, these are just things I've noticed over the years I've been working with them, so there are variables for every aspect, and they're just my personal opinions.
Best of luck with whatever you get