Florida to Southern New Mexico

I-10 is bad in Louisiana but otherwise it's OK. But Louisiana roads in general are awful so I'm not sure what you'll gain by avoiding I-10(or the I-12 bypass). In Florida I-10 is generally quite good but you could take US90 or US98 if you are in no rush.In Alabama/Mississippi I-10 is OK except for the Mobile area and I don't know of a good way around that town. In East Texas I-10 is fairly good, not up to FL standards. Houston is a PITA but I do not know of a way to avoid it. Once west of Houston the road gets better. You could divert north to I-20 but I don't know that it's better than I-10 except for LA.

We've been down I-10 to NM and points west many times over the years. Taking a guess, maybe 20 times round trip over the years.