I started as WHM and stayed like that until hitting 50 and trying to unlock all end-game content. As fresh 50 WHM in poopy class quest gear (while everyone had ST and Daystar sets (I got to 50 shortly near ST lockout removal)) I felt really uncomfortable and couldnt keep up with all that speedrunning. I still remember my first visit to CT and ST, I was solo healing both in said gear cuz co-healers were busy dps'ing/dying. So I figured I should wait a bit to get better gear and lvl SCH instead. So I rolled SCH which was pretty close to 50 anyway and ohmygod I was facerolling everything I couldnt as WHM. I still did the relic for WHM and once I got used to dungeon pace at 50 I returned to WHM cuz staff>book =3
But these days I main AST. I knew I was gonna main it the moment I unlocked it, it was pre-buffed AST and I for one wasnt even close to whine about AST being weak, I thought it was pretty good even back then. Card RNG is still driving me nuts but I find it less boring than WHM these days. I like the visuals apart from globe cuz staff is laif hehe and the amount of clutter on AF gear. Story was less boring than WHM (omg I hate WHM&CNJ quests).
I still use all healers almost equally and I still take WHM to do fast things where I dont really have time to play with cards cuz encounter ends faster than I draw 2-3cards, cuz Im both cba to draw those 2-3 for nothing and feel bad if Im not using cards %) SCH was my Alex Normal meta cuz amount of carries done since week 1 was unreal and I still prefer going in A4 as SCH.