Standby flights, risky?

[nick s]

i'm off to Thailand for my 3rd visit in April 2010 with a load of mates. Me and my gf are going on a different flight to everyone else, as we are on her dads friends and family tickets. Which are standby on BA, but if we do get on we get to fly club. Has anyone got any experience of standby? Is it usually ok, as if there;s a chance we might be stuck waiting for a flight for 3 days whilst everyone else in in Thailand already, i'd rather just book confirmed seats and pay the extra?