Throwing around pw:s while moving without rapture up isn't really viable. Cascade has a long cd and has to be used at the right time to get the most use out of it. PoM+Penance (both on cds) is hardly a lot of stuff do to while moving (especially since you don't want to 'save' them for this). Assuming that holy fire isn't made instant without the glyph and all the assumptions regarding solace are correct it'll most likely be the better option for most fights. Using the new solace+shadowfiend on cd post 5.2 should basically result in the same thing as using holy fire+mindbender on cd right now (slightly less regen than bender since you don't want to use it during shell, but if it's free this easily makes up for it) while mindbender+holy fire post 5.2 will be stuck with a 2 sec cast on holy fire.