Solid beam mounts

[RetroPug]

Without some form of actual testing how can anyone definitively say which are better?

The car "feeling stable" or "feeling good" are completely subjective. Yes, feeling confident in the car's handling has a big effect on how the driver performs but it's fairly clear from the varied responses that different drivers have different preferences. Driver preference does not actually demonstrate one or the other to be better.

Peugeot designed in some compliance toe change at the rear for a reason, presumably this was a reason drawn from a significant testing and development programme. This compliance might feel "vague" to a driver, but that doesn't necessarily mean it is bad, in the same way that very low profile tyres make turn-in feel very sharp but if you are running tyres of too low a profile you will struggle to maintain a large contact patch under lateral load and will actually be able to sustain as high a lateral load as with a slightly higher profile tyre.

Basically: how the car "feels" doesn't really tell us anything.