Tool boxes and tool carts are a lot like luggage. Sometimes you only need your wallet. Sometimes you need a briefcase. Sometimes you need a backpack. Sometimes you need a Samsonite large carry-on and sometimes you need Zero-Halliburton kick *** huge-as-f&*^ security luggage.
In small shops where each employee needs personal tools but the shop supplies a lot of them, but you have limited space, then the tool cart is optimal. Same with jobs that require very few tools but you must bring your own and lock them down. If an emplyee showed up with a 72" Snap_On rolling cab for a tiny back-room tight quarter shop, i'd send him home and say buy a smaller box or find a different job.
If you have a medium sized shop where you can use a big box and not have to walk a lot from job to job to access your tools, then you likely do not need a tool cart.
If you work in a large facility where you have to move tools daily out of a larger main box or work in a place with many employees or tight quarters where box size limits are set and possibly tight quarters, then you may need a tool cart.
I've also seen carts used as lockable storage for "shared common shop" type tools like AC guages, alignment tools, bearing pullers, etc. and then the lower open area is used for shop supplies and clean up type stuff.
For home use, If you have a remote garage or keep most of your tools in the basement or house , a tool cart is nice for storing tools per job outside the house or for keeping select commonly used tools in without jeapordizing the safety of your main storage box if put outside the house or if you do not have room in a remote garage or workshop.
I find them useful and own several carts, but it's really a matter of how you work and what your work environment is set up for to achieve the best efficiency. If working at a job that pays by the hour and time wasted walking back and forth for tools counts against your bottom line, it's best to find teh most efficient set-up and carts often fill that need.
$112.00 well spent.
Might need some tools in the house 1 day, then out to the barn the next. Tool carts don't roll well across the field. ***** when I have to make extra trips back to the garage, but when I'm done, the tools all go into the bucket and back to the garage in one trip. 
