One thing I really enjoyed: a beta, virgin hero! Michael also has an anxiety disorder that complicates things for him. Caro was experienced and that was also refreshing. The author's note at the end explaining the historical significance of 1816 (being one of the coldest summers/years recorded) was also interesting.
3.5*- not quite a 3, not quite a 4. For GR purposes I am rounding up.
Looking forward to the last book in this trilogy; the heroine Miss Augusta Meredith made an appearance in this one and she's interesting.