The AST heals are the same as sch and WHM as I've tested it (WHM being burst, sch barrier/sustain and AST being super fast heals with a little of regen or barrier). The only thing I've noticed on AST is the lack of DPS department they buffed WHM and sch is really strong DPS, and programmers now include ex/alex savage fights with healer DPS in mind so i can see a bit why people are being jobcists.

Still with the correct amount of skills they can erase any lack of DPS, yes it takes more effort (seriously see the top players and they break the estimated DPS records).