It works fine, at least with decent storage. I wouldn't try it on some super lowend box, if you you were using a protocol converter.
I've even tried pointing a host at the same storage between 2 dissimilar paths (FC and iSCSI) and multipath works fine.
--m
--Matt
VCP, vExpert, Unix Geek
--Matt
VCDX #52
blog.cowger.us