I'm going from MSP to ABQ. I think I could make the drive in two very long days by stopping in Wichita the first night.

Now at Wichita there seems to be two options:
1) 35south to 40west (connect at OKC). Because 35 runs due south from Wichita to OKC it's a very indirect route. It seems that if I went this route, the distance might be too great to cover in one day.
2) Highway 54 to 40west (connect at Tucumcari, NM). This route is more direct as a matter of geography and cuts the actual distance down, but I don't know anything about long distance travels on non-interstates--does travel time go up due to a need for lower speed?

Is 54 a road with just one lane in each direction? Would I save any time by traveling 54 over I-35?

600 miles per day is normally when I start to hit the wall on a solo drive so I'm kind of intimidated by this one.. The reason I am hoping to do this drive in 2 days rather than 3 is that this is merely one leg of a larger road trip where I'm visiting friends in various cities. First, Chicago to MSP. Then to ABQ--since I don't know anyone in between those MSP & ABQ stops I want to cover that ground quick so I can spend more time elsewhere. After ABQ I'll head to PHX, then LA, then SFO. Should be great!

Thanks for the replies