I struggle to believe anyone who went through basic training with the SA80 wouldn't notice that sort of detail. If you're that used to the shape of your rifle then any change is jarring, especially the cocking handle as it was pretty much the only visible change. That's a weapon you ate with, slept with, ran with, fired, disassembled, cleaned, reassembled, and cleaned some more.
If you served anywhere around the transition it would be more important. The change to the outside affected the way you thought of it, the A2 was much better at not jamming, cleaning was less, your confidence in the weapon was greater. Little things like the new mags and not having to fart around with only adding 28 rounds so you couldn't just bang in three speed loader strips.
