For about half of theCzech side it is motorway , then mostly 2 lane roads, its also a truck route so watch out for them passing , Not sure now but last year petrol was cheaper on the czech side so you might want to fill up there.
The last 5 miles or so to the german border is very curvy and uphill , watch out for slow trucks and crazy people going too fast downhill.
Its a nice drive if you have not seen Czech countryside,