From VNT15 to BV39 Upgrade? or not

[camboscams]

So I have a chance to buy a bv39 from a member on here and i'm wondering if it would be worth my time to upgrade. Im looking for a more efficient flow at high rpm and a stronger and better designed vane assembly. I think regcheeseman has one so hopefully he'll chime in. It is off a BRM i believe

[R.O.R-2.0]

i dont think they are much, if any better than the vnt15..