If I had something to put on mine, I would go with a new reg... but hey that's all about you. Personnaly I think the VS2 perform very well stock, that's why I'm not spending money to upgrade something working very well.
What's your style, what do you need, thoses are questions you have to ask yourself. Need more consistensy ? Go with a reg, need more precision ? go with a barrel ! There's no magic recipe...
i am waiting for a cp regulator, trinity front block and a cp on and off for my sons vs2, the stock reg gave me so many problems i decided to pretty much try it all and see what happens. right now i am waiting for the front block and reg since they are on backorder. when i get them all in the marker i will post a result.