raid 50 read latency

I've got a 6210 configured in Raid 50 connected to a bunch of esxi server. Since day one it seems the read latency has been hovering around 5-10ms and the write latency is near 0 most of the time. Sometimes VMs feel a little sluggish which I assume is due to read latency (although 5-10ms still isn't bad)

Is this normal having read worse than write for raid 50? I would have expected writes to be worse than reads for raid 50 but SANHQ is showing the opposite. My avg i/o size according to SANHQ is around 20KB and the read/write% is 35/65

Thanks