The first CD looks at trance (so they have done it the other way round this year, sneaky huh?) and the second CD is funky and progressive house.
Going for a complete CD full of trance for CD1 is probably the reason why they have stuffed it full of poor quality vocal trance tracks to fill the album. Don't get me wrong - some are good, but if you're into quality trance, theres only one or 2 good tracks on here.
If you're into comercial dance, go with this. If you're into quality trance, try gatecrasher digital trance and if house is your thing - try john digweed or pete tong etc.