Really? My mage in D:OS seemed to get a lot more benefit from speed than intelligence, especially in EE. There were a lot of very useful spells where intelligence made marginal difference, and some of the more useful spells (like summoning) had high AP costs.
We've had all kinds of other classes in the group, but none benefited from speed more than the mage and her 101 spells.
Everyone benefits from Speed. I'll put it another way: in D:OS 2, Mages are now (in essence) required to split attributes, like fighters, rogues and rangers were required to in D:OS 1. Of course I know that Mages get benefits from Speed. Before the EE, I did make an Inquisitor which was a INT/SPD hybrid which used touch spells. But there was certainly no shortage of players who made mages with Int in the 20's.
