You're going to stay in one scale for a long time anyway (C for piano). For that duration, pitches in the notation correspond obviously to fingerings (keys, frets, whatever). This includes other instruments which have a different "natural" key (D for the viola, my other sort of instrument): their notation maps just as nicely.
When you get beyond that, "mapping relative pitches to a scale" is, IMO, the correct approach. The "offset to each pitch" thing obscures what's really going on, as if they were all weird derivatives of the key of C. I can see how it might be harder, among other reasons because you have to understand how a scale works more clearly, but I suspect it would be worth it.
Of course, it's hard to really know without getting people to switch for a couple generations.
When you get beyond that, "mapping relative pitches to a scale" is, IMO, the correct approach. The "offset to each pitch" thing obscures what's really going on, as if they were all weird derivatives of the key of C. I can see how it might be harder, among other reasons because you have to understand how a scale works more clearly, but I suspect it would be worth it.
Of course, it's hard to really know without getting people to switch for a couple generations.