Here's a thread that's going on over at that other big reef site about measured PAR values in SPS tanks:
http://reefcentral.com/forums/showthread.php?t=1773012
I find PAR values get over inflated when the T5 vs MH debates flare up. Above are several real world recorded PAR values over various tanks.
Here are mine with 6x24W T5s on a Sunpower fixture over a tank that's 24 x 24 x 20 with the fixture 6" above the water's surface:
At the surface: ~ 600-700
Mid tank: ~ 400
Bottom of the tank: ~ 200