I was impressed by both ZLS and WL's performance in LLTG. ZLS's stellar acting was not a surprise for me, since I've seen her in other dramas and she has progressed a lot with each new project. WL took me a bit by surprise, since I did not find his role memorable in TLB. The massacre scene is now ingrained in my memory as the height of his acting range and complexity. He also looked very competent in action or combat scenes.
As some of you have already mentioned, I am also disappointed the drama shied away from showing a more passionate relationship between the leads. Not necessarily kisses, but emotionally intense scenes as the novel portrayed after the 5-year separation. Both were older and more passion would be natural and make the reconciliation more credible.
I don't blame WL for this because I don't think it was his choice. My assumption is that the director and script writers made the final decision. Drama LLTG turned out to be very tamed even for a historical romance and particularly so when compared to the novel.
Would I want to see ZLS and WL again in a modern drama? Yes, but after a few years. Modern or historical drama does not really matter to me as long as it's a well developed romance. ZLS has always had good chemistry with ML and, though her rapport with WL was the best thus far, I want to see her work with other talented actors. As for WL, I am curious how I will react to the relationship chemistry in his next project. More intimate scenes do not necessarily translate to an engaging chemistry between leads.