I bought a 12.9" 2018 iPad Pro a couple months ago, and at the same time I put in my preorder for a Brydge Pro keyboard. I knew when I ordered that their target shipping date was late spring, and they have sent out a few updates along the way. They have been around for a few years at this point, so I wasn't worried about their eventual delivery, but I've definitely been getting more and more impatient. Today I finally got an email with a firmer ship date!
Your Brydge Pro will be in transit to our warehouse and processing next week, and is expected to be out for delivery the week of May 20.
So excited. There are lots of preview unit reviews available via Google, and at least one (9to5 Mac) review on the consumer end unit, and it's fairly unamimously good.