Dangerous is over-stating IMO it but it's the unexpected which gets me. The worst is probably the adaptive part of the cruise control (which I don't think you can turn off on it's own). Examples - when driving around urban (30mph) on cruise control (which I have always done to make sure I don't speed) either it will brake very harshly because it thinks a parked (or turning) car is a hazard, and also the it sometimes slows you massively sometimes into roundabouts then accelerates quickly out - which can be fun but if it catches you unawares a bit hairy.
I tried the speed limiter but it has to be set on each drive, and when you corner or go round a roundabout it drops out until it sees another sign.
Any of those you can get used to - I have got used to the AC so still mostly use it but use my own feet to control the speed when I think it might play up.
I like ACC on the motorway but sometimes find myself gradually and inadvertently losing speed when approaching a slower car so you need to either maintain your speed yourself or pull out earlier. I quite like the lane assist on motorways but the "steering wheel feedback" took some getting used to.