They are definitely very different.I've only tried Outlast once and Firewire few times, but I remember like they were quite different. Looking for something in particular? Durability? Spin?
FireWire has too much grip on the ball at the expense of penetration. Good string but also tends to notch pretty quickly for me as well.Trying Tier1 Firewire in my Blade Pro and Solinco Outlast in a Diadem Elevate. Fan of them both so far. Anything else worth trying?
Haven't really been a fan of Yonex Poly Tour Pro or Poly Tour Rev in the Blade Pro.
FW is more springy and elastic than BK so has more inherent power which is probably why you like it more.I've tried Black Knight in the past. It never really stood out to me. I think I prefer Firewire, but it's been years since I tried Black Knight.
I think I did find it a bit too muted for my liking iirc.+1 for BK, since that's what I use in my VC95. But I would categorize it as a muted string. I think Tour Status might be better in terms of feel.
As for something similar to Firewire, my friend loves Signum Pro Tornado. Similarly, twisted axially.
BK is low powered, deader and dampened in feel similar to Lynx Tour.I think I did find it a bit too muted for my liking iirc.