I do believe it's good to learn and understand both secs since adjustments may be made.

When playing AST I usually just stick in Nocturnal even with a SCH. The 5% healing is pretty nice and much care is taken not overwriting shields through judicial use of aspected healing. Natural I do switch at times but few will care about the sect. Once a fresh 50 WHM pre 3.0 I've grown conspicuous of Medica II from personal experiences and watching other WHM Medica II usage. Eventually I opted for more active healing, even if it meant Medica 3 times. Single target regen used with care, medica II use at levels nowhere near most players. AST with 354 Spell Speed I take either stance, however based on the lame regen story Diurnal Sect does not share much vision with my style. MP problems? Haven't had that for a long time unless you're talking about redundant death's and unusually high raid damage, if my mp is low then sure as hell the other healer will be.