stdby:
Hm, makes sense to fit these ancient -200s with a capable FMS - that the GPS receivers are WAAS capable is an added bonus! But I don't see how fitting a recently delivered PBN capable plane with WAAS receivers would be beneficial to the operator - they can all achieve an ANP of less than 0.1NM anyway even without augmentation... Or am I missing something here?
RNP AR approaches are relatively few and require special training and procedures. And, as flexible as they can be they are still Baro VNAV approaches. LPV, on the other hand, can achieve "200 and 1/2."
One is to avoid terrain or noise issues, the other is for low minimums.