I've got one and it's ok for sizing up something that's already been spotted.  For long glassing though its not like having a good tripod.  The heads can't be locked from swiveling side to side, just up and down.  I have both heads and prefer the old style to the trigger style.  The trigger head alone weighs 20oz.  The stand-up legs don't go down real short, and the other style lever locks are loud snapping into place.  I like it as a shooting rest I can adjust ahead of time, like sitting for deer, but not for spot and stalk.
I ended up going with the Stoney Point Rapid Pivot Bipod set-up for shooting, use mostly either the shock cord collapsable ones if I'm worried about weight or the sitting/kneeling version the rest of the time.  They are quick and stable.  For glassing I got the Promaster 6160 head and 525T tripod and I've been real happy with the set-up.  It's a couple ounces heavier and more expensive, but worth it for me.  Especially if my partner stays on the spotter while I make a stalk or vice versa.