Just to be clear to the OP (and this is a semantics thing), CS/CA raise your softcaps. The reason that CS isn't a primary concern for casters is that it raises your AC softcap, decreasing the amount of damage you take per hit. As you gain levels, this will become less effective vs. other classes for two reasons. 1) silk armor has the lowest AC. 2) casters have the worst returns on over soft cap AC. So you can raise your softcap to the same levels as a plate tank but you will have far less AC because you will have less armor and will receive less AC out of that armor. The disparity grows with levels and gear. CA raises your avoidance cap, which is much more effective since you don't have parry/riposte/block and avoiding the whole hit is much more beneficial than mitigating it (and with mobs tuned to be hitting a plate AC tank, you will get hit in the high ranges anyway, just not as many max hits).
Thanks all for your breakdown. I am at CS/CA rank 18 now. Probably will just stop every 5 levels or so to max out CS/CA.
To be honest I didn't have the stomach for it until about lvl 95. It's a painful grind and some of the most unfun AAs to buy.
