In August this year we intended to get to Romania through Serbia from Bosnia, but the border guards wanted 120euro's each for insurance, so we told em to stuff it and went round Serbia via Croatia and Hungary.
We made the mistake of heading from Szeged in Hungary to Timisoara in Romania on the DN6. BIG MISTAKE!
Worst road of the entire trip and absolutely horrendous. In some places there were holes that took up half the road, most of it had "tram lines" made by HGV's that were between 3 and 10 inches deep (not exagerating). Horrendous!
On the way out of Romania were were told by other bikers that the DN7 (also called the E68) from Sibiu to Szeged was good,
AND IT WAS A HELL OF AN IMPROVEMENT!
Wish we'd found it on the way in. Most of it was newly laid tarmac. Part of it had 2 routes, 1 for HGV and 1 for just cars/bikes..... and great scenery to boot. It was very busy with lorries and campervans, but for the sake of decent road surfaces we didn't care!
My advice: Talk to other bikers coming the other way. Best way of finding out places to avoid at the very least!
Additional: If you have a Garmin Zumo 550, then note that only the Major roads (E and DN) will be shown. And not all of those will be brilliant. So buy a decent map before heading over there.