All drivers will benefit from EnABL, and except for one driver in my 35 years of experience with EnABL, all will benefit to a similar degree.
Ultra fast drivers, that "break up" with higher drive levels will be ultra fast, ultra detailed, and ultra clean for a good 9 to 15 dB above their untreated level. The performance above this point will be totaly dependent upon the motor. If the voice coil does not suffer thermal compression, neither will the sound, right out to the point that the voice coil catches fire.
Less responsive drivers will be exactly what the ultrafast drivers are, just a bit more relaxed about it, and still able to play clearly to burn out.
Really awful, boom box drivers will show a greater percentage of improvement than the ultrafast drivers, will not get to the level of the slightly more relaxed drivers, but, will still provide compelling and completely satisfying musical experiences.
If you want to have some really wonderful sound, in a very attractive package, with a cabinet you build from flats, or just final finish, with completely satisfying sound and all of the EnABL benefits, look into Planet 10 and their Fonken's with Fostex Fe 126 or 127 drivers. I guarantee you will be astounded, and will still have these speakers to hand down to grandchildren. You may build or buy others, but these will always be playing somewhere near to you.
http://www.planet10-hifi.com/
The EnABL thread is a monster.
http://www.diyaudio.com/forums/showthread.php?s=&threadid=100399
Comments from people who actually have EnABLed drivers can be found here,
Hassebaink on a Hemp 6.5
http://www.diyaudio.com/forums/showthread.php?postid=1302282#post1302282
Curvy Chang and Fostex
http://www.diyaudio.com/forums/showthread.php?postid=1354867#post1354867
Lowther DX4
http://www.diyaudio.com/forums/showthread.php?postid=1269281#post1269281
Lowther America on a Lowther PM6A
http://www.diyaudio.com/forums/showthread.php?postid=1275431#post1275431
And T Heads report on the Hemp Accoustics FR 4.5 c
http://www.diyaudio.com/forums/showthread.php?postid=1275474#post1275474
There are more buried in the thread, along with a considerable amount of quantitative information.
Bud