24 x 32 softbox too big for 580EXII hotshoe flash?

[sfogel2]

Hi, all...

I'd like to buy a softbox to use with my Canon 580EXII (single hotshoe flash in the softbox). Am considering the Lastolite Ezybox 24 x 24", but am also considering a rig for hotshoe flashes by PhotoFlex that has a 24 x 32" softbox. I wonder... is the 580EXII powerful enough for a 24 x 32" softbox (with or without baffle)?

Thanks

Steve