This was my second (at least) read of Regency Buck. There were parts of it that I liked better this time around, and parts that I actually liked less.
The hero, Lord Worth, is no more likeable in this read than he was the first time I read it. I just cannot conceive of his appeal for Judith, who is headstrong and occasionally obtuse, but who is generally of a friendly, informal disposition. Worth, on the other hand, is cold, withdrawn and often downright unpleasant. He also more or less assaults Judith on their first meeting by kissing her without her consent, an incident that is not made more appealing with threats of repetition.
She made light of the circumstance of the stranger’s kissing her: he would bestow just such a careless embrace on a pretty chambermaid, she dared say. It was certain that he mistook her station in life.
I don't find this even remotely appealing, not the least on behalf of the pretty chambermaids of the Regency, who deserved better than to suffer random groping by asshole peers taking unwanted liberties upon their persons. Ugh. There is one occasion where he actually threatens to beat her.
Do not look daggers at me: I am wholly impervious to displays of that kind. Your tantrums may do very well at home, but they arouse in me nothing more than a desire to beat you soundly. And that, Miss Taverner, if ever I do marry you, is precisely what I shall do.’
Gross. On top of that, there is no real sense that he has improved by the end of the book. He treats her indulgently, referring to her repeatedly as "adorable," in a way that is actually fairly insulting.
It seems to me that Heyer is trying hard to create a Darcy/Lizzie vibe, with the sparks that fly between them and the irreverent teasing that Lizzie uses to soften up the withdrawn, shy Darcy. Unfortunately, this doesn't work for me at all, because I just don't see Worth having Darcy's good points. Darcy seems like a jerk. Worth is a jerk.
So, as far as the romance goes, this one didn't convince me. I wanted to push Worth overboard, and have Judith marry one of the other male characters. Mr. Brummel, for example, was quite charming, as was Lord Worth's younger brother, Charles.
Now, though, the really good aspect of this book - Heyer did a great job with the mystery in this romance. Someone is trying to get Judith's brother, Peregrine, out of the way, and the way that she plotted that particular part of the book was genius. There were several bits of redirection that were extremely effective, and even the second time around, she confounded me a couple of times.
TL/DR: Keep the mystery, jettison the romance. A hero who threatens to beat the heroine is not a hero to root for.