I think that part of the 'problem' can be that they are slightly 'unusual' in the aspect they provide when they are approached.
Although 800m is ample it is probably shorter than what most folks are used to and the undershoot of both is a bit different from the average flat fields.
Combined with that you can get more turbulence on short final for both and a lot of people will therefore fly a bit faster over their normal (typically fastish) approach speed.
Hence the extended float.
FD