There have been instances of recall on certain types of detachable bars, but these were a year or so ago, and have all been modified. I think the main issue is ensuring it is correctly locked and most now have an indicator to confirm this. Cleanliness will also go along way to making it as safe as possible. The strength of the securing 'pin' is probably similar to that of the 2 mounting bolts on the normal towbars, so not much of a difference there. With the permanent swan neck, yes, but it too is welded somewhere so you takes yur choice.
I am looking to fit a tow bar to my new (at least to me) Volvo and although the Volvo one is expensive, I am of a mind to bite the bullet and just get the detacheable one.