I did a quick test with Reraise. Recast while naked: 60sec. Recast with stone: 59sec. So, it can't be more than 4%/2% because that would drop the recast to 58.8sec.--Mooffins 08:32, September 12, 2010 (UTC)
I did some more detailed testing with SCH: Klimaform recast naked and no arts: 180 sec, recast with stone and no arts: 178 sec, Dark Arts and no stone: 162 sec, Dark Arts and stone: 160 sec, Light Arts with no stone: 216, and Light Arts and stone: 213 sec. So from this, it looks to be around 98.5 - 99% of the original recast timer. So I don't know how to call this one. It's either 3%/1.5% or 2%/1% fast cast boost. --Qweenneko 09:38, November 17, 2010 (UTC)