Like...I dunno, even the softdom stuff is kinda pushing it for me. Anything that has Solas making the first move. Unless he's really drunk or something. And even then, I think he'd wait until he was 100% positive that it was what Lavellan wanted. Every time he touches her, you can see him hesitate. He's confident, yes, but when it comes to his relationship with Lavellan he's very very conflicted. So Solas grabbing Lavellan and pushing her down on the bed, even if she's totally cool with it, sets off all sorts of OOC alarm bells for me.
Personally, I don't mind dom stuff in fanfic, but only if it makes sense for the character. For example, I would read the sh*t out of a well-done and respectful Iron Bull fic that features dom/sub stuff, because that is in his romance already. I also think light femdom works really well for Hawke and Fenris. Solas, though? Not so much. Anything with him being controlling just goes against his entire characterization. He doesn't want to control anybody, let alone Lavellan.
What I can see is him being very experienced. And to portray a sexual encounter between an experienced and a less experienced partner without getting into power dynamics is tough. But it's doable if you go about it the right way.
It's the tension between passion and hesitation that makes Solas's romance so wonderful. It's very...subtle. And I guess I'm not surprised to see the fandom at large missing that subtlety, especially with all of the Fen'harel baggage. It's a shame, though.
But every so often you get stuff like this, which so perfectly encapsulates that tension without needing to put it into words. So browsing tumblr for Solas stuff is still worth it.
(vaguely NSFW)
Oh yeah, this art is perfect. Now "Hallelujah" has started playing in my head for the umpteenth time today. 
I have to say, in my headcanon, Lavellan and Solas never actually had sex (of any kind). This is not because I'm opposed to smut, but because I think he wouldn't do it, not without her knowing the truth about him. In the end, the best gift he can think to give her is a bit of truth, which makes me think he's constantly anguished about/keenly aware of his lies (and, ya know, the situation in general). In fact, I think what causes him to break things off so abruptly (and excruciatingly) w/ Lavellan is because he senses they're about to reach a point of no return.