I probably shouldn't say anything so I don't give away my secrets..but I pretty much never offer surrender, even for kids and girls, assuming I still have paint and/or propellant. Getting shot is part of the game, and I will not overshoot and do my best to aim for a hard target, but if I miss and tag something squishy, it ain't gonna kill ya. People are pussies these days..if someone starts shooting you 4, 5, 12 times that's something different, but a couple balls up close is not a mortal injury.
That said I will regularly "surrender" charge if I'm unable to continue shooting (broken gun, no paint, etc), and it's probably 50% effective, a bit more if I still have air and can shoot blanks as quickly as possible while yelling/charging. The other half of the time I either end up with a 1 for 1 when the (usually newer) player surrenders and shoots me in the chest simultaneously, or get shot out by the player or another member of his team during the run.