I ran a Vf48 on my 07 wrx for three years, the last year with meth. The second summer my 3rd gear decided to leave me (car see's a few 1/4 mile track days a year) which I then upgraded to the 6spd.
The car with just the turbo, sti tmic, walbro 255 and an e-tune got me a best time of 12.81 on all season street tires. I never got to run the vf with the meth tune, but it was a good bit quicker than without. The vf is a great jump in power over the td04, you will love it.
I just upgraded to much larger this year after my stock ej255 lost a ringland and I went to a built engine.