Compared to the F90, the G90 does feel a bit hit and miss. Its insanely quick for something as heavy as it is, but it doesn't feel fun at all to drive. The F90 really was peak BMW M car of the turbo generation, I'd hold onto this if I were you for life.
I went for a ride in the G99 Touring and its absolutely massive. Feels like you in a boat on wheels. Don't really like the way it looks either as its giving too much of Mercedes R Class Vibes from a few years back which was more or less designed to be a hearse.