For a single stat, the maximum bonus is linear - the ^1.5 inside the sum and the ^2/3 outside it cancel.
Assuming a full set of gear designed by a player able to pick exactly the stats and mods wanted so long as the item stays within the budget, caster gear still looks good to me. They don't get weapon damage, but every other slot gives more and there are a lot more non-weapon than weapon slots. Unfortunately players don't get to design items. Hopefully there will be plenty of +damage in future additions, I agree that adding Int/Spi after reaching 'enough mana that you won't run out' is pointless.
While recognising their power, I don't like the effect +single school items (and single element focused talent builds for that matter) have on gameplay. It's simply more interesting to use several spells in rotation than to spam a single spell. Shadowbolt is probably the worst offender, since using it with talents can proc a bonus to it's next four casts.
I don't know what to think about potential Spirit improvements. I like the stat on my Druid thanks to Innervate; If I respec I'll need to throw out most of my healing gear - without Innervate, Druids actually gain less from Spirit than other casters. It's useless on my Warlock. I'm not sure whether I would use it on a Mage - 45% regen while casting is pretty nice and I've been musing about trying a Spirit focused build with one.
Assuming a full set of gear designed by a player able to pick exactly the stats and mods wanted so long as the item stays within the budget, caster gear still looks good to me. They don't get weapon damage, but every other slot gives more and there are a lot more non-weapon than weapon slots. Unfortunately players don't get to design items. Hopefully there will be plenty of +damage in future additions, I agree that adding Int/Spi after reaching 'enough mana that you won't run out' is pointless.
While recognising their power, I don't like the effect +single school items (and single element focused talent builds for that matter) have on gameplay. It's simply more interesting to use several spells in rotation than to spam a single spell. Shadowbolt is probably the worst offender, since using it with talents can proc a bonus to it's next four casts.
I don't know what to think about potential Spirit improvements. I like the stat on my Druid thanks to Innervate; If I respec I'll need to throw out most of my healing gear - without Innervate, Druids actually gain less from Spirit than other casters. It's useless on my Warlock. I'm not sure whether I would use it on a Mage - 45% regen while casting is pretty nice and I've been musing about trying a Spirit focused build with one.