I would say that you should go for ba cos after a while u can go longhaul and still do shorthaul, and when that important birthday or event comes up you could wangle a shorthaul route! where as with virgin you couldnt! Plus i think that ba is more of a company then a brand like virgin! its a hard chioce i know! i wish i was in your posistion and had those offers!
Good luck with what ever you do! xxx