jsippy73 I've driven 550 miles of I-40 many times before I moved to Las Cruces from northern VA. From where I 81 changes to I 40 and then through Little Rock AR. Other than Tennessee is relatively low speed limit (65) and many TN State Troopers. Driving through Knoxville and Memphis is easy but I usually take the 840 bypass around Nashville. The bypass is 42 miles (I think) but overall I found it saved up to 20 minutes and avoided some delays of less than 10 MPH driving.
Overall, no issues. I use Marriott only as I have status and many reward points. I typically do 1000 mile days, so stay outside of Little Rock where it changes to I 30. Overall Arkansas is cheaper hotels vs TN, plus when I pay I use Govt rate and AR govt rate is low. AR immediate west of Memphis is not a safe area, even some stations just off I-40.
I stopped using Buc-ees after I tried twice in TN, too many people and the traffic set up to get in/out is time consuming mainly because of the traffic. They are first rate stops though. However, no windshield washers, very odd.
I go I 30 down through TX to New Mexico, depending where in CA you are going, TX has higher speed limits to make time.
Joke in New Mexico is, if you have half a tank, it is emergency fuel time. Surprising lack of gas stations in the state even on the three main Interstates (I 10, 25 & 40). I have driven all three a lot. DO NOT stop in Albuquerque, hotel parking lots are easy auto crime areas, auto crime is a career in NM.
No toll roads where I traveled. Lots of single lane construction points but never really impacted time.