I have been running on VTA for a while for my HKS, and for the past few days I finally managed to get all my piping correct to have it running in BPV mode.
Pros:
-no more backfires (no more melting my cats!)
-no more running too rich
-butt dyno says the car is running smoother and stronger
-I can now hear the turbo spool up quite loudly (perhaps meaning it's holding boost better?)
Cons:
-a lot quieter...no more "pssh" sounds and the car is generally less grumbly
-my recirc piping is not set up 100%, so it might pop off soon (this is a case-by-case basis)
I've never found the car to smell bad even on VTA...I also miss the sound a lot since the "pssh" sound from the HKS is the signature of a turbo'd car. I also have a Fujita F5 CAI as well, for those interested in my setup. I might go for a testpipe later (or maybe just a resonator delete). Shifting also feels the same.
