Opinions vary. We took the Gulf Coast route once and hated it and will not do it again. I think maybe it depends on the size of the rig. Many now take the route from Laredo down the center of Mexico through the Monterey area and around Mexico City and over the mountains. The roads are all pretty good but there are many tolls. There are lots of things to see along the way and lots to do. We know of no low clearances. In Mexico they have the Angeles Verdes (Green Angels) a fleet of almost 2,000 small repair trucks driven by mechanics patrolling the roads to help motorists/tourists who breakdown. They do basic repairs and only charge for parts or fuel. They will know where to get more repairs if needed. Many toll roads have tow trucks and ambulances at each toll booth ready to race down the road in emergencies - special phone numbers to call for help. Many new roads in Mexico are as good as many interstate highways in the US. There are lots of threads and stickies on this forum that will tell you almost all you need to know.
We do not know of an RV park or place to park an RV in Akumal. We stayed up the road a ways at Paa Mul.