What amps are you using? I think the parafeed design typically has a little better damping than the classic single end, and also a better quality output xfmr is nicer, but you'd be fine either way with a well-designed amp. I also think that the "honest" xover design and the fact that there's no drastic dip in the impedance curve in Pi 4's is helpful with smaller tube amps. No offense meant with guru comment- I didn't know anything about the other guy- just kidding around. Hope that was clear by the smiley! You'll be quite happy with the Pi 4's.