Georgette Heyer's mysteries are really not particularly good. They aren't as bad as I've heard some say they are, either. They exist in that realm of "entertaining, but stick with your strength." They're all English Country House mysteries in which everyone hates hates hates the victim (who deserves it) and most suspects are relatives. They're also very prone to making sure that, in the romantic plotlines, we realize that the guy is way way smarter than the girl. The romantic plotlines are also of the Sekritly In Love With (For Years) variety at times. Most books follow the same formula pretty closely, and they're entertaining. Though Heyer's formula is pretty standard for the time, but...well...I like the formula for manor house mysteries of the time. That said, Heyer is rather awkward with people of her own time, and the dialogue sometimes reads as if she's having to write people of her own time, not the Regency or Georgian eras. Actually, I sometimes pretended that somehow cars and telephones were in the early 19th century.
Read over a longish period and individual comments made as I went along, so there's no doubt some repetition and contradiction mixed in. I think all but one was an Inspector Hannyside book, though I think I read the last book with him first.
Why Shoot the Butler?: This was the first of Heyer's mysteries that I read, and it was a bit disconcerting after the few of her romances that I've read, especially when she seemed to be going for the same feel for the dialogue. As implied by the title, this is a country house mystery in which the butler can't offer up vital clues because he's dead. That's really the main thing that sets it apart, aside from a later death that I wasn't expecting. It was fun, but the main character was literally a passerby who came across a young woman and a corpse and always felt a bit out of place, and I kept going "Wait, why are you here? Oh yeah, you're The Detective?" and wondering what his beef (Heyer's beef?) with country constables was. Ok, he and his connection were eplained, but I kept forgetting.
The Unfinished Clue: This is one of those mysteries where every single character hated the victim, who only died after we got to see why every single character hated him, and no one had an alibi. I admit to a fondness for these plots. The twist with the killer was pretty easy to spot, but then, it hadn't been used nearly as much in 1934. I thought the protagonist worked much better here, as did the dialogue, though that could have been because I adjusted throughout the previous book.
A Blunt Instrument: I read this and enjoyed it then got sick and forgot 90% of the details. I think this was when I realized that, while the mysteries themselves are technically good, Heyer's mysteries are actually on the flat side, and that the character relationships tend to be better than the plots and that the books are at their strongest when the characters almost seem to have been in her romances and then got lost. This one, though, had fun antics where people started thinking their spouse/sibling/potential S.O./best-friend-from-third-grade was the killer and started trying to make themselves look guilty instead.
No Wind of Blame: In complete honesty, I actually just found the characters and their antics utterly hilarious for a lot of the book (though I wouldn't want to get caught up in their stuff at all) and kind of forgot to pay attention to the plot for a lot of it. I did think the "ho he did it" reveal was a bit "ooooooook then..." though, and rolled my eyes at the possibly-fake-prince a lot.
Death in the Stocks: This book is when I realized that these books aren't really good. Ok, I knew that, but I like the mystery plot types Heyer uses. But Heyer really can't write people of her own time well, even if they're still entertaining. But! A man is stabbed and then bizarrely moved to the stocks! His brother wants to be the prime suspect because he thinks it'd be fun! His sister is bragging about destroying anything that could incriminate her! Another brother returns from the dead! The very grounded cousin/family lawyer and the inspector had migraines. The villain was easy to spot by being the only character the nrrative didn't want you to like and/or find fun.
Behold, Here's Poison: I kinda of love that "behold" as in "BEHOLD! PAY ATTENTION!" is part of the title here? I think I'm glad I ran out of books, because while I enjoy Heyer's basic formula, I started really wishing she'd shake it up more. I could not figure out how the poison was administered, which was nice. Also, Heyer remembered that servants actually have names and personalities in this one.
At some point, I apparently read Duplicate Death, but I don't recall a single thing about it.