My M3 just accelerates hard when u click it up 5mph.
Yup my old 147 GTA did that, I went to set cruise when I spotted some Police up the road in a 30 to make sure I did not speed, accidently did resume which was set at 75
resulted in my first speeding ticket as it was pretty quick off the mark, Doh 
Volvo is smooth probably very similar to Polestar.
but I like to keep my distance generally and those distances narrow depending on speed. It slows to a complete stop and will carry on when traffic is moving, although depending on traffic speed this might open up too much of gap and I generally turn it off at that point. It's only tried to kill me a few times
flat bed truck and going around a bend up a hill on the A30, both things are mentioned in the manual!