Sonic Frontier Line 3 X Bat VK-30

I agree the SF3 is more to my liking. I own the Line 3 and auditioned the VK30 at length (not in my home system) My impressions were:
1. VK-30 better imaging
2. SF3 better tonal resolution
3. SF3 better extension, particularly in the base
4. SF3 better harmonic texture
5. SF3 better S/N ratio. (Less hiss)

Both a very good pre amps.

try to listen to it with the music that you like. I personally like the SF better. But it is a matter of taste and system match