Garrus romance is probably the healthiest female hetero romance BioWare has written; or at least one that you could say without a doubt would last until they're old and gray. They did good with him.
My FemShep wasn't interested in him in ME1. The way he dealt with joining in ME2 was a huge contrast to how everyone else from ME1 dealt with it. Super loyal, respects Shep. In his LM he showed he had a mind of his own so he isn't a doormat either. I would think he grew on me after the LM. Felt like paragon choices saved him from "ruthless calculus".
He's also vulnerable but not broken. A lot of the romances have super broken people with issues that they emo over forever. Garrus has his insecurities too but he's got more quads than any of the other LI (well maybe Liara too) that I've seen. Kaidan, Jacob, and Thane were the only other hetero romances a FemShep could engage in and Thane comes in a close second in my book to Garrus. Kaidan is useless in battle (or at least to my playstyle), the lines with Jacob in ME2 turned me off right off the bat, and Thane is second-choice because...well...

Plus I'm fascinated about the nose scrunches turians do...very interesting. But I agree on the physicality thing. BioWare was very tasteful in the Garrus romance scenes. You notice small physical gestures between Garrus and FemShep but not overbearing skin/scales/whatever. My fiance saw Garrus' facial expression before he dipped FemShep and kissed her and he said, "That dragon's got smooth moves."
I squealed and said, "I know!" while clapping frantically at my PC screen.