I work in the mining industry though we provide our own tools at my current mine. I've used company tools at other places. Here's my thoughts on things:
Warranty:
Warranty and the hassle of how to warranty things should be taken into consideration depending on the structure of the company you work for. Some of the bigger places I worked at just order something new instead of trying to warranty a $25 tool. I work at a remote property in Alaska, town is 2 hour by boat and there's not many brick and mortar places to warranty stuff. I have to deal with shipping broken stuff out/ chasing down warranty issues on my days off, if it's cheap I don't even bother trying to warranty stuff. If it's something I break frequently I just buy it from snapon because we have a local rep and I can meet up with on my days off, he's easy to work with and doesn't ask for a receipt for a tool I haven't bought from him. Trying to find receipts from 3 years ago and spending half an hour on the phone is a pain in the **** and I've bought it out my pocket. I can't see most of the guys I work with dealing with the hassle for a company tool.
How many people in the department and will their be a guy responsible for tool maintenance/ warranty stuff? Will they be able and allowed to track down an original receipt, contact the vendor, and get the warranty initiated? Also how's your receiving department? If a warranty tool shows up without a PO is it going to disrupt their world? What I'm getting at is depending on the company and how cumbersome things are warranties can be a waste in the corporate/ industrial environment.
If you are going to warranty stuff having a rep you can contact directly who hopefully visits weekly would be something to consider. The guys can throw broken tools in a box, the rep grabs them weekly and shows up the next week with a replacement bypassing the front office, receiving, ect. and your guys aren't spending an hour + to get a $10 socket warrantied. You'll know who your vendors are who will work with you. The tool trucks who mainly deal with automotive shops may or may not be able to work with you. I believe snapon has industrial guys who sell to plants/ municipalities though don't deal with automotive shops. I know my rep can sell to the mechanics at the city garage though can't sell directly to the city, I don't believe he can sell directly to the mine either.
Complete Industrial Sets:
Every brand offers a master set, they throw a lot of stuff in you may or may not need. I've never looked at a set and gone that has everything I want and nothing that won't get covered in dust because of lack of use. Your maintenance guys should have a pretty good idea of what they do and don't need to do their job well. The last mine bought their mobile mechanics proto kits, there were a bunch of odd ball tools left after boxes had been picked over.
Brands:
-Williams. I have their supercombo full polished wrenches, they are amazing, my set goes to 1 1/2" in full polished and 1 9/16"-2" in stain. They work great, feel great, and I haven't broken one yet. Their black handled screw drivers are nice, I've broken a couple from abuse though a snapon blade fits a williams handle. I don't have any experiance with their sockets or ratchets.
-Grey Pneumatic, most of my impact sockets are GP. Most of their socket kits go bigger than a standard kit, my 1/2" deep standard goes from 5/16"-1 1/2" which the range is really nice, my 3/4" set goes to 2 1/2" when most sets go to 2", I do find my self using some of the bigger sockets. The only GP socket I've broken was a 3/8" drive 5mm allen, a new one was $10 on amazon so I didn't try and figure out where I bought it for warranty
-Proto. I've ended up with some older proto stuff, I really like their adjustable wrenches. I've used a lot of older proto wrenches and sockets from sets, they hold up decent though are very clunky compared to other brands.
-Gear wrench, I somehow haven't broken a gear wrench ratcheting wrench in 2 years, I have some of their sockets and the chrome is peeling. For an industrial setting I'd consider this stuff throw away junk.
-Snapon, I have a great rep he'll warranty things like broken chisels and brass drifts no questions asked. I find it's often times the same amount to buy something once from him than twice from somewhere else. The convenience of seeing him face to face is why I buy snapon, not to mention they are great tools and just plain work.