I think its pretty much personal taste. I tend to time my exit to coincide with running out of fuel on the same turn, but will occasionally stay if I can be a useful decoy. Unless its a really hopeless situation (manoevers damaged against 3 Snipes) I tend to try and fly on when damaged, coz all that's about is not getting shot at.
On whether you take advantage of sitting, fuelless ducks, I used to spare most, until i got hacked off with other people shooting me down, so I tend to show little mercy nowadays. But, generally I'll still wave off a great pilot, rather than shoot them down - sorta brings back the chivalry thing of honouring a worthy foe.
All trademarks or tradenames used in this Web site are the property of their respective owners. Material may not be republished, nor may content or images be mirrored on another server without written permission.