I think the current romances are by and large fine. Shadowheart's is obviously the sweetest, boy meets girl, the works, it seems intriguing because SH is this kinda vulnerable secretive chick. This could evolve into a romantic story with slow progress, but we will see what Larian does with it.
Astarion's really works because he wants to manipulate you and he really does strike me as someone who would just use people for his own pleasure. He has the superficial charm covered as well. Him being a vampire also has implications, he may ask you to be his bloodbank. His condition also triggers my saviour complex, and I imagine I'm not alone when it comes to wanting to "save" him. Of course I think Astarion expects me to want to save him so there's that, but his romance seems like the most solid so far. I actually approve of him hitting on everyone, because he IS a user. When he wants something it's never about you, it's always about him. Leaving him as a psychopath is just as compelling as saving him, if you get involved with the guy, drama is guaranteed and I love it.
And now to Lae'zel... Well she's ugly (no I don't care that you disagree), and she has this obnoxious "raarh strong woman" attitude that is just very repulsive, HOWEVER, her sexuality fits that mold perfectly. She is basically an angry dude with breasts, fancy hair and a big sword, and frankly, the only thing that could make her character more repulsive is if she ended up finding a soft spot in her heart for you. Not only that but since Gith apparently lay eggs that presents some interesting problems about their anatomy. As far as I know, creatures that lay eggs have cloaca, both the males and the females, so that would mean that a male gith would only differ from a female one in the aforementioned breast area when it comes to sexual organs. This would also support the idea that sexual relations for gith are not romantically and emotionally involved affairs. As much as I hate Lae's romance, I just hope they don't make it emotional because it would just make it even worse.
Gale's and Wyll's are really not finished yet, so I can't really judge them beyond thinking that Gale's is boring, and Wyll's is uh... weird?