I'd rather be given a Centurion-D (even if it is the stock build) than a Centurion-AH.
3 simple reasons:
1) Giving a newbie a mech that is totally ammo dependent is a hard sell. It's not something you give to a new player because they still have to learn the weapons, but also ammo management. Usually efficiency takes time to learn.. with energy you don't suffer from ammo problems. So, it's not as useful at first glance.
2) Centurion-D is expensive C-bills-wise, compared to other offerings. Selling it for parts would be more valuable to everyone involved.
3) 300XL on the Centurion-D is very reusable for many mechs (including the Yen Lo Wang).
Mind you, there are probably other better reasons, but the Centurion-AH as a gift/reward isn't really valuable unless it's another "Loyalty" variant (at least for the C-bill bonus).
Edited by Deathlike, 22 December 2015 - 04:23 PM.