Through my "old style" Octane HD, I've used the Fiocchi 158s in both my BW5 and my SIG P239. I used it sparingly in the BW5 for concerns of breaking the roller retainer. The ammo shoots very quiet in this combo, but then again so does any subsonic ammo. In the SIG, I had a dramatic POI shift using this ammo through the Octane. I'm talking like 6 inches low at 7 yards. I found that the powder used is not very clean burning. I was getting a LOT of powder and carbon backsplash in my face. Combined with the extremely dramatic POI shift, I won't ever buy this ammo again.
The Federal AE 147s meet all my needs for the Octane on the MP5 clone and the SIG pistol. It runs cleaner than the Fiocchis and the POI shifts are negligible. Until I can find a comparable load in bulk for less money, I'm sticking with what works, and it's not 158s!