Please don't mistake me, I completely loved mythos priests! They were among my favorite things to play! But looking back, I can totally see how there was a serious problem with their implementation, when you can play a priest out of Legends and Lore and be handed abilities of other classes like warrior Thac0 or exceptional strength, or the ability to cast Wizard spells, let along unique abilities like "oh hey, it says here I get -1 to AC per level until level 10!" (Hermes, I believe) or "huh, so at level 11 I just...go to level 12?" (Sif).Specialty priest were one of the most awesome concepts in D&D, and have never been equalled. Execution can always be better and is subject to preference in any case.