I was on a completely packed LAS-SJC flight on Sunday (they even took volunteers off after we boarded, it was 137).

To of the last 10 or so people to board both had guitars with them. You know how much baggage they had to rearrange to get the guitars stowed towards the front of the plane? None, there were two bins in the front of the plane with plenty of room. I ended up putting my computer in the overhead before pushback, since the one above my seat was only 1/3 full.

I certainly notice that overhead bin storage is much less of an issue on WN than other airlines because bags fly free for everyone (certainly some flights still have problems, especially on -300's and -500's, but on average it's less of an issue), I doubt I'm the only traveler who notices this. Of course elites on other airlines get their bags for free, but I think it is also inarguable that bags fly free for all passengers benefits everyone.