I just needed a 3-RU rack-case to hold an acoustic guitar preamp, digital reverb, and power amp, but my SKB case was about 4" too shallow for the power amp.  Didn't want to go to a full 21"-deep case for space considerations.  The Gator solved my problem.  Molded from high-density military-grade polyethylene, with two solid handles.  There are heavier-duty cases out there, but this one met all my needs, and for 30% less $$$ than a comparably-sized SKB.  Where just a few RUs are needed, the Gator's are going to be my choice from here on.