I believe this is the first ARM Cortex-M fabbed on a 40-nm process (not counting companion cores on Cortex-A SoCs). Previous ST chips were 90 nm and I think the fastest M7 to date (Atmel/Microchip x70) was at 65 nm. It will be interesting to see how the power efficiency compares at various clock speeds with, say, the STM32L4 series, when feeding the ~ 1V core supply from an efficient switcher.
H7 also inherits one of my favorite weird peripherals from the L4, the DFSDM (hardware CIC downsampler). And the claimed specs make it sound as if the on-board ADCs may have improved their noise performance... let's hope so.
Edit: SPI peripherals unchanged, with shift registers still limited to 16 bits. Makes it difficult to interface a wide range of modern ADCs. Old IP dies hard I guess.