I-75 or US-64/74 to MV

[Cajunrider]

I planned my route to MV last year but I've been looking at shortening it up some. I will be following I-59 up from Slidell and spending the first night somewhere around Tuscaloosa, AL. From there I will follow 59 up to Chattanooga and was wondering if I should continue up I-75 to I-40 at Knoxville then down to MV or cut across on US-64/74 as South Cleveland, TN to Waynesville, NC. The reason I'm asking is I will be pulling the trailer and riding 2 up and don't want to get on roads that would be difficult to handle the trailer. I prefer to avoid the slabs but don't want to get in a bind with the trailer in serious switchbacks.