I've put the vf48 through a pretty good test so far.
The Forester has been driven across country from the mid-south, through the Rocky and Cascade Ranges, out to the Pacific coastline. I've clocked about 8,000 miles since the turbo swap 2.5 months ago.
Compared to the td04, this turbo pulls great through the mid and upper ranges. There is an insignificant hint more lag than the td04, but the torque is much greater than stock. The tune tapers slightly toward redline due to having stock injectors, but the turbo still pulls strong and consistently.
The main issue I have when accelerating aggressively, as compared to the td04, is how easy it is to get to 90-100 mph.
I'm quite happy with how this setup feels. After this experience, I intend to have them upgrade the vf37 for my ej207 wrx instead of purchasing a new BPT 1.5xtr.