Only getting a couple of hundred IOps per 15K drive isn't really accurate because in reality we don't do a fully random workload across the entire disk.

I wrote the blog post here a few weeks ago because I got fed up with SAN / Storage engineers I couldn't possibly get the number of IOps I am getting out of the kit at one of my clients: http://dataidol.com/tonyrogerson/2014/04/07/maximum-iops-for-a-10k-or-15k-sas-hard-disk-drive-is-not-170/

For a 100% read work load of 64KiB on a 20GiB file on a pair of 300GB 15K disks in RAID 1 with a Queue Depth of 32 I easily get 2,281 IOps. For 8KiB I get 14K!

It really does depend on what you are doing, if you are doing sequential scans and you've performed the correct defrag maintenance on your tables, set them up correctly the disk head doesn't need to move too far so IOps goes up - dramatically.

Hope that helps.