I gave it a 7, but I'm biased as my Cleric of Cuthy 2 has it.
I think it's of great use at low levels, and peters down to good use in mid and high levels. Right now, with 13 STR and a Medium load (wearing Banded Mail) I move 15 ft per round. With this, I move 25 ft a round. While this means I can't outrun anything in light armor with a speed of 30, it also means I can outrun anything in medium armor and encumbered slightly. The possibility of needing to escape is a very Real thing in many campaigns- where DM's state clearly "Just so you know, you may encounter things that could tool you (ie the world doesn't morph around you to suit your APL's EL.)
As far as I'm concerned, the +2 Con is just gravy. If I can one day get a +4 Con Amulet I might, or I could invest in a Natural armor one instead. For now though, the mobility in combat is excellent.
For nods from the peanut gallery, just ask any of the people in my party I'm supposed to heal who would be out of my move ranges (hustle or run).