I didn't mind ENT confirming the KBoP was specifically Klingon. I never liked the theory that it was the movie-ized version of the RBoP. The color, the head, the downward-canted wingtips all seemed distinctively Klingon-y. It looks more like a squashed and stretched D7 than a lumpier RBoP.
While I also agree that the KBoP looks more like a Klingon ship than a Romulan ship, what annoyed me was the whole bird-motif thing. It was originally established that the Romulans had the bird-motif at least as far back as the Earth-Romulan war, and continues into the late 24th century. While we all know the flip-flopping in TSFS with the BoP (and then the BoP becoming a generic Klingon ship in TNG until they built the Vor'cha), ENT then goes on to retroactively establish that the Klingons also had the bird-motif all the way back then as well, but for no real reason. The odds that two completely different alien races had the same motif for their ships is astronomical, and makes no sense.