From where we live in East Texas it is usually either I-30/I-40 or I-20 which we have to take depending on whether we are going straight east (I-20) or northeast (I-30/I-40), so we have a lot of experience on this part of your route.
I-30/I-40 from Texarkana to Memphis is one of the most heavily traveled in terms of 18 wheeler trucks in the nation. The one time I would NOT want to be on that stretch would be with rain. The spray from the trucks would be blinding and it is not unusual to find trucks running side by side in passing. Still if we are going northeast this is our route. Little Rock is easy to get around and that is the only city between Memphis and Texarkana.
I-20 has a few rough spots as far as pavement surface and therefore has a bad reputation--just above I-10 in Louisiana. I don't find it as bad as some. Just slow down through Jackson, MS and approaching Shreveport, but there is a good bypass route around north of Shreveport. I-20 is certainly a better approach to Fort Worth than I-30, for what that's worth. Traffic has always flowed freely around south of Dallas the many times we've make that route west--nothing like 635!