Alright, this is going to read like a headache, so I'm going to give you a fair warning on it before I start.
Gravitation... Really does not live to the hype. I've read lots of BL manga over the years, and have watched my fair share of BL anime as well. I have tastes of what I like and gripes about others I don't. However, I consider myself pretty open minded and tolerable when I pick up something new. Especially if I've heard lots of good things about it.
This reads like a stroke. This is most likely just translation errors and myself not understanding what exactly is going on a good portion of the time, but it reads like a stroke. I'm reading this all in English by the way as a native English speaker. Although I really do love the art from the 90s and early 00's, I really do not miss the writing from that time. It's not just BL stories that suffer from it, but there seems to be a majority of BL from that time that is written like a nightmare. I can't really explain it.
The characters... God... Some of them are pretty one dimensional. I was reading this today and I still can't tell you most of their names. The only two characters that seem to have some of their sense is the Producer and Hiro, and that's really setting the bar low. My biggest gripe is about Eiri Yuki, and... Oh I forgot the main character's name. Uh, Shuichi. Don't get me wrong, I think like Shuichi sometimes, I'm not going to say I have all my brain cells together, but... Wow.
I'm 7 volumes in. Seven. Volumes. And you still cannot make me believe the relationship between these two is realistic, capable, and healthy in any sense of the word. I understand that Eiri has PTSD and a bad past, believe me, I do... But there is no reason for him to treat Shuichi the way he does. I sat and tried to rationalize it, coming from someone who does have PTSD, among other things. Maybe he just had bad coping mechanisms? Maybe he has other illness? Maybe he really does have a kind heart, but just a hard exteiror... Not really. Any good points that Shuichi brings up, is no where near enough to cover up all the bad parts of him.
Not to say Shuichi is any better, but he's more like a helpless kicked dog than anything else. He chases after Eiri, I'm not sure why, but he does. Maybe Eiri isn't my taste, but the amount of times Shuichi chases him is... Exhausting. Eiri just drops him like a fly and runs away, but then comes back and still treats Shuichi more like a sex friend than a real partner. I have Borderline. I drop people and run back to them over the smallest bits of paranoia, but I was finding this so exhausting to the point where I could no longer sympathize with the characters. I couldn't figure out why go back to someone who dismisses you constantly. Why chase someone like that? Once, maybe twice, I get for stories like these, but I've counted maybe 3 to 5 times where something akin to this happens.
Shuichi is probably one of the dumbest protags I've met. I love silly dumb protags, I think there is a lot of comic relief potential for them, and they make for great people you want to cheer for. Shuichi's dumbass-ness supercedes all of this and it makes you want to smack your head in the wall. When you learn a BIG SECRET about your lover, most people will sit on it and think about it, you know? Especially if it's something THAT bad. Shuichi pays it almost no mind. "Yuki is Yuki." Yeah... But you're not going to think about how you know SO LITTLE about him and when the most crucial bit of information you get from him is this... Run away, my guy!
I'm not so much a fan of abuse, but I'll take it if I think the story is still really good. Sometimes people write abuse great and it shows, and sometimes people write abuse and it sucks, but the story is still good regardless. Gravitation has neither of these. While it does explain a bit more about Eiri and adds a bit of drama and suspense... It just feels like that's... It. The story is still not good with it being there or with it not being there. Maybe it was to cater to a particular type of fan, or maybe I missed the message there, but it turned me away for a bit.
To sum up my crap: The pacing feels like a nightmare where I cannot figure out what is happening, the writing is not very good, the plot is sub par at best, the characters are not well drawn out and are flat, major relationship red flags (if you care about realism), and overall... It's just a boring read. There are better stories out there, BL and not, for this time era. Gravitation is overhype hot garbage that if I wasn't dedicated to finishing, I would have stopped at volume 3. But hey, at least the art is nice.