It is intriguing. I agree. I was on a ramp yesterday that was signed as 10%, and in fact the Garmin said it was 11%. Maybe the sign was wrong. Either way, whether it tells me the instant the pitch goes from 9 to 10 back to 9 is not really that important to me, even if it lags a bit. That at a glance I can get a sense of the steepness on hills that aren't marked (most of them), that's been good enough for me in practice. It strikes me that 1040 does a better job with gradients than the 1030 (cannot compare to the + since I never used on). This could be due to the gyroscope (tilt sensor?) it has on board, and it not depending solely on GPS and the the barometric altimeter. Same for speed, using GPS to know your speed is never very accurate, due to nature of GPS signals and how weak they actually are. Running a speed sensor helps, but even then, the speed seems to "bounce" around a bit.