Haste affects spell recast. So yes, 9% haste would be good.
HOWEVER, for Rune Chopper's effect to be active, it needs to be draining 3 MP/tick. And in most circumstances, that is simply unmanagable.
Using one will just show you know little about your job. I'm sure you can get haste on your gear so you wont have to ditch your Elemental Staves... you know, the thing that gives you a +15% boost, or your trial thing that gives even more...