Extremely believable depiction of what an alcoholic goes through when trying to battle it out, especially in the 19th century when they wouldn't have known how alcoholism worked or that it was even a disease. Not to mention that it was actually expected for a 'gentleman' to drink all the time. This brings to mind the 1950s idea that smoking was 'cool' before understanding all the negative health issues it actually brings. 
 As for the love story, the slow pacing in which it occurred was also credible as too often romance authors make the mistake of having the main characters fall in love almost the minute they lay eyes on each other, which can become a repetitive drag. Real people usually become interested in each other before actually falling in love, or fall in love due to the character's virtues and flaws, which is what happened here. 
 All in all, the reason I gave it 4 stars was mainly due to the originality in having an alcoholic hero in a historical romance whilst most heroes are perfectly in control and never have major vices. It made the story have more grit, which is always a welcome change in the usual white-washed saccharine romance world.