I've been with Virgin for just over 12 years and I have no desire to ever fly short haul again. The long haul lifestyle isn't for every one either.
As things stand I'd consider your potential move very carefully. If command floats your boat I wouldn't come. I'm as they say in VAA "Ready for Command" and have been told it could still be at least another 2 years away, so I'll have been here for 14 years. That time is only going to increase and anyone who joined after about 2003 is going to be looking at 16 years depending on what happens with the 787 and 330. If you join today I can't see anyway you would have a command in under 20 years.
As to a lifestyle choice it's been much much better. However these days most FO's are lucky to get more than 10 full days at home on the 747 and on the 340 it's creeping down to about 13. However virtually everyone I fly with is, as you would expect, fun to be away with. Depending on the destination the crews can either be great fun or just disappear. More often than not I end up having a good time.
People will talk about expansion but it's not going to happen. We have less aircraft today than we did pre 9/11. VAA has reached a natural plateau and I don't see much expansion. Coupled with the fact we're out in the cold as far as Alliance Partners are concerned the future is far from certain. As long as Virgin continue to operate with a specific "niche" market we may be ok.
People have talked about job security. There isn't any! Every time there is a downturn VAA lay off as many people as they can get away with and they don't care because they know there will always be a stream of young starry eyed aviators who want to come and fly a big long haul aircraft. Some people are put out by this but frankly that's business when you are a small private company.
I have no regrets about joining Virgin but if I went back 12 years to talk to myself I'm not sure whether I would advise doing it again.