Dior lambskin is much more resilient than Chanel lambskin apparently. I have several Dior lambskin bags in various colours and they don't stain like vachetta does if they get a few rain drops on them. If I have been caught in the rain with a lambskin bag I tend to dab the wet areas with tissue to absorb any moisture. Unless you are caught in a downpour I think they are fairly hardy.
In terms of scratches I think it can depend on the colour you are getting (black may show scratches more easily) however again, the lambskin of Dior bags is pretty resilient and if you condition your lambskin Dior bags this may buff out some of the scratches and also soften the leather.
Also be aware that the quilted cannage will over time flatten; I'm talking at least 10 years down the track though. If you look at the particular bag you are interested in on the pre-owned sites you might be able to see how they wear. I don't know the specific model you are looking at but the New Lock pochettes wear extremely well. The flap may start to sag a bit but if you store them correctly this may be reduced. The main area which wears on the New Lock is the corner which rubs agains the wearer and the top corner where the flap starts. This is my personal experience with my black lambskin New Lock pochette, and the other new lock pochettes I have are in excellent condition considering I use them A LOT.
Hope this helps.
