The OCE version is also available as a free download if you have access to a fat pipe.
The 2.0 release is older, uses old kernel and has some restrictions (I have read that "fixing" those is pretty easy though - like the CD-ROM burn speed).
The 3.0 Deluxe version uses new kernel, new KDE and new everything else. I also think you get Crossover as a part of the package that allows you to run certain Windows programs if you are in the "moving over" phase and you think that you will need to read office documents etc. 3.0 also includes support for more hardware than 2.0.
2x533MHz@544MHz, 2.0V
640MB PC100 memory
Realtek RTL-8139 NIC
Maxtor 6Y080L0 80GB hdd
Debian Linux stable with 2.4.8 kernel