Ultra 94 sucked a couple mph out of my trap speed, actually. It's lower in energy density than 91 Canadian Tire - which is 100% gasoline, no ethanol. Additionally, I believe the CT is more than 91 octane, to be sure that they don't face liability questions...
Either way, my car works best on 91 octane pure gasoline. Ultra 94 is something I use when I get it... but independent testing from Porsche tuners in Canada says that Ultra 94 has similar knock characteristics to pure 91 octane pump gasoline (from Shell, but that's no longer a sure thing either, apparently).
When I put some 91 octane in the tank from McKewens, I had the car pull ALL power when I put my foot down entering the 401, presumably because of detected knock. That was interesting for more than one reason.