I will review the roads on parts, because the surface is different from one section to another.
Sighetul Marmatiei - Moisei - the road surface it´s excelent
Moisei - Iacobeni - the road is terrible(it´s practicable only for adventure bikes; I recommend you to go on DN17C Moisei - Nasaud - Bistrita)
Iacobeni - Vatra Dornei - Bistrita - very nice road, good asphalt, nice views
A magnificent mountainous, until Vatra Dornei the road condition is perfect giving high speeds with lots of open corners enjoying the same time the great scenery. From Vatra Dornei towards Borsa (45km appr) the road is really terrible with lots of holes and dangerous spots, be vigiland, but the scenery is amazing (altitude appr 1400m, Tihuta pass). The Maramures region is a UNESCO protected region due to the traditional wooden churches which can be found mainly after Borsa towards Sighetu Marmatiei.