I have had a BDM for about a decade.
Pros: Thinnest double-stack I've ever seen. Super reliable (albeit I've only ever used it in range-type conditions; never done any dirt/water/mud/extreme temp testing). Decent sights. Decent trigger for a DA/SA, smooth OOB. Field strip is very easy. External decocker/safety.
Cons: The mini-beavertail is somewhat low on the gun; if you have a very high grip, you may find it to be in the way. The manual of arms is a bit unusual. The safety is also a decocker; the gun cannot be fired with the safety in the safe position, and placing it in safe while the hammer is cocked will decock the hammer. The safety also acts as a slide release (putting the gun on safe releases the slide), although there is a (small) dedicated slide stop/release. Down is safe, up is fire, so you cannot ride the safety as one can with a 1911/BHP/CZ. Available magazines are mostly aftermarket things these days, and some of them require some adjustment to get them to run right (I had to dremel down the front edge of the last one I bought - I'm no gunsmith and I was able to take care of it fine, so it's merely an inconvenience).
Conclusion: Great gun if it fits your grip. If you're going to use it for defense (and it's a terrific carry gun because it's so thin), you have to spend some time really making sure you are comfortable with the manual of arms.
