CloneCD copies Diablo II with no problems.
You need a drive that can read audio and data track subcode data. My Toshiba DVD-ROM drives do so just fine (SD-M1212 and SD-M1201).
I burned the Diablo Play CD using a Plextor 12x4x32x SCSI CD-RW. I have never used the master Play disc to play Diablo. The other two discs, Install and Cinematics, were copied fine from Adaptec's Easy CD Creator.
Unreal Tournament uses SafeDisc protection. You need a drive that can read and write errors. Again, my Toshiba drives can read errors just fine (takes about 15 minutes to image UT), and the Mitsumi CR-4802TE I used to write my backup disc writes errors just fine.
It all comes down to what your software and hardware can do. For backing up my games, CloneCD's not let me down yet.
http://www.elaborate-bytes.com is their main site. Check the hardware requirements for CloneCD to see what is compatible.
Just my $0.02