[Pictor]

I went from a 2018 M550i to a 2020 M850i GC.

Engine: The M850i has the newer engine with more HP and its noticeable.

Exhaust: The M850i sounds better (from the outside) than the M550i which I though was too tame. Neither are loud.

Ingress/egress: No complaints on the M850i although the headroom getting into the rear is a little bit tighter on the M850i due to the lower roof line.

Interior space: The seats are more snug on the M850i. I'm reminded of the Sport seats on the E39 540i/6 that I had. The seats are comfortable and snug. I haven't done a long road trip yet but I don't see the seats being a problem at all.

The surprise to me was that the rear seats have more legroom in the M850i vs the M550i. That said, the M850i is really a four seater and I couldn't see myself asking anyone to sit in the middle - although technically possible.

Driving dynamics: The cars are very similar although the heft is felt in the M850i. I wish the tires where about 2-4 cm wider front and rear because of both power and weight of the car. The suspension feels different. It's tighter (roll) due to eARS but softer in some situations (pitch) which I also think is a result of eARS. I didn't have eARS on the 5 because I haven't liked BMW's ARS implementation on past 5-series where the springs where softer than the M-Sport springs.

I didn't have IAS on the M550i and it's a standard feature on the M850i. I'm not a fan of the IAS but it's also convenient for daily driving. I just have to keep second guessing what the rear wheels are doing when going through a spirited turn at certain speeds. It's not a deal breaker but if it was an individual option then I would not get it again. Our G05 X5 also has IAS and it feels better suited to a longer car like the LWB 7-series or X7.

Cost aside, the 8-series GC is a really good alternative to the 5-series.