They seem to have more ram (1184 vs 1024 or 692) compared other H7 series parts.
As well as the max clock speed is "only" 280MHz.
The A3 and B3 look to be the fully fledged parts with up to 2M ram.
The B0 parts are the value line ones that only have 128K flash like the H750 parts
Has a GFXMMU peripheral (graphic memory management?)
OctoSPI support
the H7B0 has 2 OTFDEC peripherals "On the fly decryption engine"
PSSI interface (Parallel synchronous slave interface)
Seems to be about it from what the cubemx is bringing up.
The peripheral clock mux mess looks to be about the same as other H7's