I like DFFv1 much more than V2.
Low end boost is there, but not as much as V2. I like it more because it sounds to me like it more localized to the true bass region (<60hz) as opposed to v2 I think it bleeds into the low midbass which creates a muddy sound to me.
vocals sound good, maybe not quite as prominent as V2, but the mids dont accentuate the electric guitar range as much either, which is good because I thought that V2 got screechy/too loud.
Highs have a little sparkle. Just enough that it seems like there might be a small boost here, but its done with restraint and I like it.
I only have 5 songs on V1 as im writing this, but it may be my favorite unamped FW. Overall, I'd say go with DFFv1 over v2. Ill give it a couple days before I say this officially, but it may be my favorite FW so far (at least with the limited music i've listened to on to this point)
Also @CoiL I just gave v1 a test with Mars Volta - Deloused in the Comatorium -Take the Veil (Cerpin Taxt) and do not find V1's guitar overpowering, which can happen easily with the Volta in my experience. Also, you reminded me how amazing this whole album is. Take the Veil is one of my all time favorite songs. (I just got to the guitar into bass solo into the last breakdown and I am loooooving this FW)
Anyways I highly recommend V1 and am neutral (at best) to V2.