Any wax is better than none at all but to say the average skier can notice a difference at lower speeds is a bit of a stretch.
Nope. Not a stretch. Absolute truth. A never-ever will notice the difference between a ski with low breakaway speed and a ski with high breakaway speed.
The never-ever will think that the ski with low breakaway speed is bad. They will not be able to step forward. They will backslide on little humps. They will overshoot the lift loading area. They will hate the skis. But they WILL notice.
The never-ever will also (eventually) appreciate a good wax job more
because they slow down to a crawl as they shop for turns.
Many of the members here are above average skiers so they probably could feel slight differences just how much and at what speed is difficult to calibrate.
Anyone standing still and shuffling their feet forward-back can tell a wax job with low breakaway* speed.
*Not my term - official TOKO wax manual term for the speed at which a ski escapes static friction and goes into dynamic friction.
It's important we use official terms now that we're officially spansered.
You do have a point - once the ski is in dynamic friction, few people can tell a good wax job - and this was my point above wrt. racing and maximum speed.
Once the ski is in dynamic friction, less than half the posters to this forum can tell a fast wax from a slow wax without timing or a pace skier. Maybe. I doubt there's even that many. Terrain, snow quality, line, ski flex and damping, structure (as
@Chenzo points out) are all so much bigger factors that anyone who thinks they can is probably fooling themselves.