Actually if you listen really closely, you'll notice that the engine runs very slightly rougher with the code stored. This is mostly noticeable at around 1400 RPM.
Also....if one looks really close at the program that is in the ECU, yes, it does "derate"-approx 15% with PO336. It has to do with how the crank sensor is ignored and then the cam sensor does the work-but the cam sensor is a LOT less sensitive as to the rotation and position, for one reason, gear lash. The clearance between the teeth of the crankshaft drive gear, idler gear, and then the cam gear...it's nowhere near as accurate (from a positioning standpoint) as the flywheel-which has about 90 holes drilled in the perimeter, and is bolted directly to the crankshaft. These engines need to know the position of the crankshaft to within about 0.25° of crankshaft rotation-which by the way, if you know what to look for in a datalog, you can see the crankshaft rotational "twisting" in the graph of the crank sensor. And you can see the speed change of the flywheel from a cylinder power stroke, then the "dead zone" between one cylinder's power stroke and another. It's that sensitive. But the cam sensor is not.
On the L2501, I like them. Same physical size, less torque and less power than the 3301 (considerably) with quite a bit more noise. The engine is loud and that's my ONLY complaint with the 2501.