VVN550, burn rate, physical appearance, performance is almost identical, depending on lots.
I have both H100V and N550 on hand and I've left a note for myself to try some identical loads in the same cartridge with once fired cases and identical primers, bullets from the same packages to compare them for performance at the range.
Likely won't happen for a month or so, couple of gunshows coming up. Chilliwack Mar 15/16, Penticton and Kamloops in April.