I purchased this rack case to try out a more expensive alternative for Gator rackmount cases. Here's my opinion.
Advantages: sturdy and reliable, well-made butterfly latches, more room for gripping with your hands (unlike Gator cases, this SKB case doesn't pinch your knuckles if you have relatively big hands like me), has gaskets to protect your gear from liquids or small solid particles, the retractable handle stays well fixed in the lower position. The case has rack rails on the back as well, which is a must-have. Being a 4-rack-unit size, this case can be safely put vertically with lids open when you don't have enough space to put it horizontally. Even with the lids open, your rack-mountable devices stay well recessed inside, so you can even put the case with the front lid open facing the ground without damaging your equipment.
Disadvantages: heavy for a non-plywood case, expensive, the wheels perform very poorly when you roll this case over slightly uneven surfaces (not to mention tiled froor with joints), there's a lot of vibration which is not good for your gear, so I prefer carrying this rack case, not rolling it. the wheels of Gator cases are much better and roll smoothly like those of inline roller skates.
Summary: if you suffer from Gator cases pinching your fingers or knuckles when you use the side handles, go for SKB; if you need great wheels, then get a Gator case. The best of both worlds would be an SKB outer shell with Gator-like wheels. The wheels on this SKB case are replaceable, but I never got to replacing them. I think at this price point the wheels should be like those on Gator cases or better. Would I buy this SKB case again? I think yes, but I would consider a lighter version without wheels as they are almost useless (too much vibration).