Well a backup isn't technically "required", but just recommended.
But the reason I ask about wiping is because the instructions are a little lacking. This ROM is fairly stock, with (as far as I can tell) just some modified system APKs, modified framework and other tweaks - none of which would indicate that a full system wipe is required. So it might be possible to just install on top of stock and wipe cache/dalvik without wiping everything. I'm not sure if the OP meant you needed to wipe if coming from other (ie: non-stock) ROMs or anything including stock.