Acumen potions

[zoopp]

Has anyone noticed  that acumen potions give you less casting speed than Acumen/Chatn of Flame even though all 3 have the same 'Effect 3' ?

Here are 2 screen shots:

http://img682.imageshack.us/i/96393488.png/
http://img28.imageshack.us/i/87404719.png/