If you are an 'average guy,' I doubt you'd have bought a 5900, let alone a 5910. The 'average guy' doesn't spend $1500, far less $3500. Most guys buy mainstream players, and few are even aware of such issues as CUE: many don't notice it until it's pointed out to them - then they can't ignore it.
If you're looking at a 5910, or 5900 even (or 3910, 59AVi, SP1000,..,) then I would expect you to be a discerning enthusiast, who is looking for the best affordable solution. One who has identified shortcomings/failings/flaws in 'lesser players,' and is looking for players that overcome/eliminate them.
You (one) shouldn't just buy the more expensive player because it is said to be better, unless you can see and appreciate the improvement, and consider it worthwhile. If you can't see the difference, or if it is of no significance to you, then you could save money and buy one that you find satisfactory, then deploy that money elsewhere.
I would suggest a demo disc is being produced, not to prove a difference exists for those who can't see it, but to conveniently highlight the key advantages obtained for those aware of common shortcomings.
There is a difference. One person will see it, another won't. One will care, another won't. The proof of the pudding is in the eating: you have to see it and compare it to your reference, to see if it produces a worthwhile improvement to you, that's worth the asking price.