I am a keyboard and mouse player, with all three healers at 80. For me the answer to; 'Is AST bad?' is; 'Yes, AST is bad'.

Prior to the 5.0 changes I preferred to play Scholar or Stone Mage over AST because:

It's sound effects make me feel sleepy. Honestly, the tinkerly little sparkly flutter of malefic and combust combined with any low level roulette make it horribly difficult for me to keep my eyes open.

After the 5.0 changes my opinion of the class changed from; 'Its good but I can't keep my eyes open.' to 'Its bad.' the reasons being:

I have to dot something or otherwise engage an enemy before I can use a card on player or I will not gain a seal.

The seal system isn't fun. The old card system was, I really liked burning cards for potency, duration, and aoe modifiers. trying to get the right set of seals, feels more like rolling dice then drawing cards to me. not sure why. But I don't like it.

AST feels like it takes twice as much attention and work then SCH or WHM just to get the same performance. Which might be fine, except those damn sound effects are putting me to sle..... Wha... What was I typing about again?