This is so far the best Georgette Heyer I have read, it does indeed have something of PG Wodehouse and as most of her books, you will read it over and over and over again, enjoying the witty dialogue and the elegant prose.
Yes, you do have to suspend reality to understand why Rule marries Horry, but who cares?
By the the middle of the book I was already in love with the Earl of Rule, the most wonderful Heyeran hero I've come across (I've only read 10 or so of her books yet). I laughed outloud with some of the wonderful duel scenes. In terms of the plot it seems as though this is a much funnier, well thought and better written version of the "April Lady" plotline. Pelham is 20 times funnier and lovable than Dysart, and having a villain to spice things up much more engaging than Lady Letty's hysterics. You do not want to slap Horry (which I did Nell), except for the stammer... and Cardross mopping after Nell and pouting is not match to Rule's daring and wit.