I currently have the atera which like andermt I wanted because of its light weight. It is well built. My only complaint is that putting more than two bikes on is a bit of a brain teaser.
The atera (&thules) will need the support straps as shown in andermt’s photo for >2 bikes otherwise it will swing about. This is because they clamp around the tow ball.
The pendle attachment is alot more sturdier and drops in to a holder behind the towball. The pendle is bombproof as long as you grease the sliders but is heavy. I think (but not 100% sure) that they may have an attachment for goosneck towballs.
Atera will fit gooseneck & witter towbars.
Not sure about thule – they used to be gooseneck only. They would just about clamp on to a witter but sufferred from droop.
Weight not being an issue I would go back to a pendle. They are also easily fixable if you ding it (reverse it in to a wall like me)