Of course, a lot of people will watch this drama for the BL theme, all of the couples being very lovable, however, I would recommend this drama for the storyline. I have yet to watch another drama with a similar storyline - though drama's with reincarnation as the theme are popular, they're not like this. This drama made me cry in almost every episode the first time I watched it and I am not someone to cry to TV shows.
I gave the acting an 8, not really because I found the acting bad, especially not Fluke and Ohm, but more the way the scenes were set sometimes, some scenes could have been cut shorter to get to the point quicker. However, if you don't plan on watching a whole series properly, this is not the series for you as you need to watch every episode to get the story and it is most definitely a slow burn.
If you have the patience, I would most definitely recommend this drama, I have watched it multiple times already and would happily watch it again.