ive been using a craftsman tool cabinet at my factory job for 8 years now. The welds are breaking loose and i have to bend drawer tracks back with a pliers every now and then. They might be good parked against a wall in a garage, but when you move them from point to point on a daily basis, they do not hold up. I would imagine this is ESPECIALLY true with the thousand pounds worth of tools a mechanic has. (i know, im also studying automotive technology right now)
Ive talked to several people already in the automotive industry, who have LOTS of tools, and have been using their snap on/mac/matco cabinet for decades..
you get what you pay for..