I just looked at the pictures we took back in 2008. After leaving Fundy NP, we picked up route 915 so we could visit the Cape Enrage lighthouse. We rejoined route 114 further east and went on to Hopewell Rocks (which is a don't miss). The pictures don't show a lot of hills, but my general recollection of the secondary roads in NB and NS in general is that these roads tend to follow the terrain with little cut and fill to smooth out the up and down. The road surface back then was not good in some areas, although some of the pictures do show good road.
IMO a visit to Hopewell Rocks is worth a few bumps.
BTW, the road from route 915 up to Cape Enrage was a real twister with some very steep sections.