Disclaimer: I guess these romcoms aren't my thing, I also had some issues with the series 1000years old.

Let me say OMG Vampire is much better than 1000y. but not very good either. It's ok, not rewatchable. A show you can watch while washing some dishes or something (unless you don't know Thai like me and have to diligently read the subtitles). My relationship with the series is very mixed. There are highs and lows. On the positive side, the chemistry between the couples and the main characters is good. Unfortunately, the antagonists and supporting characters seem like foreign bodies. Also: why is the blood that Guv.Lux drinks blue and glowing? And the End... It reminds me a lot of Game of Thrones season 8 Finale.
So all in all, I give it a 5.5, but only because of the last episode, because there was finally the sexual liberation of Poom and all the loose ends were tied up.