Just put in an order for a New Designz 05 roller trigger, Critical paintball do a similar one where you can adjust the point the optical sensor engages on your trigger, looks like a bloody good idea, and I'm forever screwing with my trigger so this looks good.
The Ti rammer apparently has a few problems, maybe look at a lucky valve kit, but not sure whether theres any point on a nexus.
Personally, I'd whack in a new trigger (dependant on preference) then spend the rest of the money on other kit or paint. You've got a pretty decent gun to start with there.
And if you want to save batteries, you can get overdrive kits for halos (I figure there'll be something similar for vlocities) that change your drive ratio, in theory improving battery life. Getting one of those for my halo too, so will report back
Russ