I worked for Knight for almost the entire year of 2016. I can add some basic facts as to my time working there.
*always a lack available empty trailers. once you get to know areas around the terminals, you can go to a local shipper and locate one. But it takes time, time you don't get paid for.
*the rivalry between terminals is pretty bad. they say there isn't, but be from Denver and break down in Ontario. they'll let you sit for days for something as simple as a water temp sensor. 15min job. ask me how I know.
*the equipment layout is basic. BASIC.
*pay issues every week, but eager to fix any discrepancy.
*the fuel mileage bonus is an easy game to win when you learn how to play the game. only get enough fuel on a load to get you to your destination. if you don't need fuel, don't get it. fuel mileage is calculated by fuel purchased per load, not what the truck actually gets. if you fill up on a 200 mile load, your fuel bonus goes to hell. but if you top off between loads (needs dispatch approval but they never say no) it doesn't ding you as bad. they also have end of week fill up opportunities based on fuel price shifts or billing cycles. take advantage of them.
*dispatchers and terminal managers (in aurora anyway) were laidback and did everything in their power to keep you moving. mechanics were decent, and services only took an hour or less. my dispatcher kept me deep in loads. sometimes two or more lined up back to back.
*the are safety driven, and don't want you to work outside of your comfort zone. if you can only handle a couple hundred miles a day, that's all they will give you. but if you can consistently put down over 500-550 a day, you will be in the top spots on the driver board. thereby getting the better loads.
*DO NOT BE LATE to a pick up or delivery. even if it just a drop and hook at a lowes depot. it will decrease your ability to get the better mileage loads.
there are some other things, but not worth mentioning. overall it wasn't terrible there. I was getting nearly 12000 or more miles a month toward the end. I had to leave for personal reasons, but if I was a newbie I wouldn't take them off the list. do your two years then move on.