I've had my X5 II for about 5 months now and I have two 200GB cards in it with approximately 18,000 songs from around 1800 albums. I have been listening to it as I go to sleep for an hour each night on random and, though I'm usually asleep before the hour is up, I have been paying close attention to the songs and artists I do hear because I'm testing how quickly I can name a song or artist for music I have not heard in a while. Getting pretty good at it.
What I have noticed though is that the random feature is not random enough and I have been hearing songs from some artists way more often than I should and nothing yet from artists for which I have lots of albums. Example - I have 20 Led Zeppelin albums yet have only heard 2 songs so far and I have several bands which have only 1 or 2 albums yet I've heard up to 5 songs from some artists so far. That's skewed towards that smaller artist. Sure I like that artist but I figured I'd have heard less from them so far.
I know with an iPod you can sync with iTunes and it will report what songs have been played so you can see what's being selected and in the several years I have had a few iPods I can see it is spread out pretty well with the bell curve showing more songs from the artists with more albums. But there's no way to see what the X5 has played so I can't prove what I am hearing. I just know if I've heard one small band last night, I probably ought not hear them tonight. But I do.
I think the random function needs to be checked to make it more random. Not sure if anyone else is seeing this behavior but it's something I notice and figured I'd ask.
Kevin