sfo:

perhaps 991 GT3 is not as strong as expected ... 

Exactly.  Porsche, for decades, has built a wild-child variant of the 911 and the new 991 GT3 seems to have moved away from that formula.  While the new GT3 is a very capable performer on the track, at least according to the numerous and favorable reviews, it seems a bit too cultured and refined to carry the badge.