I think that there should be more than one playlists.

I have more than one type of music that I enjoy, and they don't really mix that well when played back-to-back. And going through and selecting thirty or forty songs to put into the playlist each time is a little time-consuming.

The "shuffle" doesn't seem to work very well. I semi-often get the same song played soon after a second (Song A, Song B, Song A).
And it seems to avoid other songs like the plague, (do they have a virus? [haha]). Is there a way to "shuffle" through them till all have been played once, then start a new shuffle?
In this vein, I've also noticed that one can put a song into the playlist multiple times. Whether this is intentional (or if it actually increases the likelihood that the song is played twice as often, it is a good thing. I like some songs more than others, and I'd like a way [albeit easier*] to make sure that some songs are played more often than others.)
*and more importantly, easier to oversee, (as in a way to list the songs from most-playable to the least wanted).]

Anyway, thanks for the product, guys. It is one of my most used and enjoyable programs. I'll try to buy it soon.