I like many others have used Akismet since converting to Wordpress many years ago. I've been extraordinarily underwhelmed lately by the number of false positives it's turning up. Because of that, on some of my more trafficked sites I've needed to add extra layers of protection to cut down the levels of spam. Right now for the first time I've had to look at getting a new Akismet API when I discovered it's now a paid plugin. Thanks to all the comments here (particularly Christoph - thanks!) I'm going to start moving away from Akismet to Antispam Bee. I'm so glad I found this post.