That's totally dependent on your budget for time and money. If you just can't scratch that itch for more power, think about installing the TGV deletes, TMIC and phenolic spacers and get tuned. Those will allow for a little more power, but probably also a smoother delivery of power across the band, as well as being good stepping stone mods before going with a bigger turbo. Make sure you do your research before choosing TGV deletes to make sure everything is going to fit right in the end. Some brands don't have enough clearance to refit a 3" turbo inlet. Phenolic spacers seem to do a good job and are relatively cheap, so don't forget those. It's a good opportunity to install them while working on the TGVs anyway.