I thought Crit will still go through block, so you are still running some risk at floor 10. For this reason I actually have more success with dual sword since it delivers the kill before too many critical happens, giving me the time to heal up in between. I made Dual Shield Unarmed Necro, only 77 block but 17 life leech, plus rift to kill zoos. You can probably guess how that went. Just another one of those "only dies in floor 1" build, but you can solve all floor 1 issues with wand lore/coral wand. Oddly enough both dual staves psionic and dual shield necro got pretty low rating when I put them on wiki.