I’m assuming you’re referring to this:
If you choose AE over Mabie then Glentress will seem even better when you get there!
(Don’t)
I’d bet at least a beer that he meant it tongue in cheek.
Ae is a good trail, maybe a bit of slog if you’ve not been warned in advance. If I had the choice, then Mabie is a better option for a first time visit.
Basically – go to Mabie.
And lastly, as said above the GT black diversions amount to exactly what a lot of (most?) folk do to reduce the climb on the the black. You do miss some good bits- but not the best.
And lastly, if you find the black “dull” – you’re going too slow!