It seems to have some problems that force people to use folders to navigate. Clicking on an artist doesn't bring up albums by that artist or am I misinformed? Can you play more than one album at a time? Slightly different topic but does it support replaygain? Also is gapless working for mp3 and flac? I'm still considering one but there are some things that I really don't want to give up. Right now I'm enjoying a rockboxed ipod 1st gen nano line level out to the E11 amp to my Westone UM2 in the ear phones. Crazy setup but works very nice. Also just got a sansa clip zip to play with. Pretty amazing for the money and it does everything I want. Not for critical listening but good for most uses. Ok sound quality, adding rockbox to see if it improves. It would be nice if they came out with a rockbox version for the X3.Sorry about the off topic but I think I wrapped it back in at the end. :-)
To answer a couple of your questions:
I can play by artist or album, no problems there. Eg choosing 'artist' daft punk brings up all songs by them regardless of which album they are in and can play them all.
You can also select an album to play from start to finish.
One thing I did do before the x3 arrived was to use mp3tag to tidy up the tags within my music files using a standard convention. I think this has helped in avoiding issues.
Scrolling through long lists to get to the song/album you want takes a long time, there should be a feature where the scrolling accelerates more the longer you hold down an arrow button.