Actually, I'd say that any serious rider who can't feel it is either oblivious or numb
Because reasons I have been rotating 2 wheelsets that are about 300g difference between a couple of bikes for the past month...and it is very obvious. If one has the resources to buy or build a light wheelset that will hold up to their riding - ignore the envious haters and more power to you.
In answer to Tim's question:
Using alu/alloy clinchers, even with low spoke counts on track hubs - No! I have been playing around with this same idea for months myself - like I already said, I feel the difference in my wheels so I
want another light set, just with a wider interior than I have - and the best I could do (theoretically by adding claimed weights) on my latest plan using new, not unobtanium, not inexpensive bits is 1365g.
I guess you might get where you want to go with shallow crabon toobies, but since I haven't actually shopped/researched those - it is just a...guess