@Naruto depends what you are looking for they both awesome cars but give a very different feel. I own a F80 comp and have driven a dealership’s G80 RWD and a friends G80 AWD (albeit it was a 30-40minute drive) and I feel like the F80 is more direct drive , u feel the M car more, it is harder/stiffer suspension but it is an M car - you want that!
The G80 looks is a love or hate (It is growing on me but I am not quite there yet). When I drove it, it felt a lot more “smoother” if I can say than the F80 but did not offer the same driving experience as the F80 maybe it was the suspension or maybe I needed to drive it a bit harder Im not sure. People talk about it being a bit numb at times I guess that is it. It is probably more comfortable if u have a long commute to work in traffic but as the other guys mentioned, I think the RWD versions are the lesser loved and might drop in value soon while AWD version are in the 1.6m region so that is a big gap from a F80 with plan which will be roughly 1 bar. The other thing I noticed on the G80 is that they could have made the stock exhaust sound a bit louder but I like it loud lol! G80 was newer tech but in-car usage of tech wise you wont miss anything. I would love to get a G80 one day but as a buyer I would only look at AWD like most of the guys have said. Go drive them all and take ur time, it is a-lot of money so don’t rush it and wait for the one u want.
How are you planning to use the car? Mileage u will do per month etc?