I'll echo BE-86. There was an Alliant employee on one of the other boards who made some comments. IIRC (feel free to correct me if I am wrong), Unique, Power Pistol, and BE-86 are all in the same family. In fact, I believe Unique and Power Pistol both have BE-XX identifiers. One common complaint about Unique is that it could meter better. BE-86 is a smaller flake, and meters better. I believe BE-86 falls in between Unique and PP in terms of burn rate (in the right spot for 40 S&W). I have used BE-86, Unique, Power Pistol, and Bullseye. They are all great powders. Finishing up my last bit of 32 lbs of Unique. Of the three, Bullseye is the only one I personally wouldn't use in 40 S&W (too fast). I've never found the need to use magnum primers with the Alliant flake powders.
To do bad things, I've recently got into Longshot. Behind 135 gr Nosler in 40 S&W It really wakes that cartridge up. What does 40 S&W do that 9x19 doesn't...How about a 135 gr bullet at 1500 fps inside SAAMI pressures.