I have only ever owned one T17 title, so I am not sure about this, but...
...isn´t there a possibility that the copy protection won´t transfer well on ADF? This happens to be the case with SEUCK for example. So there is a valid reason to use a cracked version.
The WHDLoad installers are designed to work only with non-cracked games, to stop people installing pirated games.
Because most games are simply standard disk images with one copy-protection track, WHDload images all the tracks
except the protection track, and disables the check for that track in the game.
In other words, it doesn't solve the problem of satisfying the protection, it disables it completely - so a normal ADF would be just fine.