I must say, I deeply distrust them. Maybe the bland statements we have read, that they appear to pose no additional danger to cyclists and pedestrians, are skewed by the fact that a lot of cyclists do take extra care when near one of these vehicles, so the accident rate is reduced for that reason. Certainly I would never filter past a bendy bus, whatever the circumstances. I do sometimes filter past a rigid bus, if I feel it is safe (i.e. the bus is well back in the queue of stationary traffic, and I can see the lights). Maybe other cyclists are also scared to get near them, with good reason!
Several cities in the UK now have articulated trams, but these pose a different sort of threat. A tram cannot 'left hook' a cyclist in the same way that a tyred vehicle can. But then of course there are the rails... A cyclist really has no business riding along a tramway anyway, I deplore urban signage encouraging cyclists to do just that (if there still is any - I have seen it in the past).
Luckily for me, in our area we have none of these monsters. The only bus services locally (which are infrequent) are rigid single-deckers with a capacity of around fifty. And these are often half empty. I don't use them. And they don't trouble me much.