get-scsilun call performance

I'm trying to determine how many devices are attached to each host in my environment.  When I call (get-scsilun -vmhost XXX).count on a 4.1 host, it takes around 4 seconds to complete.  When I make the same call against a 5.1 host, it takes around 74 seconds.  What can I do to improve my 5.1 host calls?

Thanks!