Black spot prone but shrugs it off and puts out new leaves. I'm still going to use it with healthy varieties for moss. Paul Barden's 'Unconditional Love', an F1 of Scarlet Moss, is healthier in my garden than SM is. I'm using that one as well.
It's a beautiful rose and I agree a good subject for hybridizing unless you hate prickles. That's the main problem I have with the Mosses in general. They are lovely to look at but not very pleasant to work with.