All in all, highly recommended, good deep reads worth the time.
Bartholemew and Michael are a good pair, they allow for plenty of exposition without interference. There's a pretty good environmental tension, what with the Plague and the pressures of the times.
The murders aren't overly far-fetched, the solutions can be hectic but are never completely random. There's good groundwork laid, if you know how to look you can see it coming, but it's not spelled out either.
Character development is reasonably well done, though sometimes the endings are actually too tidy.
Many historical "small details" are broken, so be ready to research anything from bathing habits to foodstuffs, the colors of daily life are stereotypical but rarely accurate to what we understand of the time and place.