I have DFL, MRT, PC3K and DDI and for now I can't imagine my work without PC3K. Why??
Well, stability - very very few crashes or bugs.
Functionality: even today I got a WD Fblite with locked SA. In about 10 minutes I make it to work (that included read ROM from USB PCB, write on SATA PCB, unlock SED, create a task, decrypt and start imaging).
Even on other brands, I found it very much more mature tool than MRT or DFL.
MRT have a great potentiality, but the lack of support (the forum is dead), bug repair, stability doesn't make me change from PC3K to it. I just use it for imaging drives.