Agreed, this episode and the last one were both huge improvements! I did think the actress who played Clary was marginally less grating this week, but maybe that's because her dialogue was written a little better. She's definitely still the worst of the bunch, though.
What little we got of Harry Shum Jr. this week was wonderful. I didn't start watching the show for him, but he's the highlight of each episode for me. I can't wait to see more of him next week!
Jace was a total dick in this episode. I haven't felt all that sorry for Alec until this week, but Jace was rough on him. I guess I should just be grateful that he's developed a personality since the first few episodes, because even though he was a douche, at least I had a reaction to him at all. Watching him and Clary interact is still worse than watching paint dry, though, so I'm glad there wasn't much of that tonight.