Do you think J6P cares that his movie uses up 60% or 90% of the available space on the disc?
When the average buyer perceives PQ is the same, he/she will look at price, features, available titles, ease of use and connection, and maybe a few other factors. PQ might not even be at the top of the list. And when he sees Disney releases are only on Blu-ray ..........
I would say that the reasons you gave will not really come into play either. The average consumer will not have any idea what features, connections, etc are available. Many will purchase a player and connect it with a composite cable to an SD tv set. I think that the price point will have to get very low (maybe less than $200 or even less), then something unforseen will happen, such as Paula Abdul in a drunken slumber talking about her new XXX player and how good it looks. If you talk to average consumers about available space, Universal only HDDVD, Disney only Blu-Ray, PQ, Menu Features, or whatever they are going to be turned off and wait longer to purchase anything.