Keep reading I will get to a point eventually
BSD commonly has less drivers than Linux, in particular multimedia devices and so on; fewer people using it, who care less about those sorts of things. NIC, HBA etc drivers, no problem - USB webcam drivers or TV dongles, pretty much nothing.
Linux has all these things; we looked on enviously at things like MythTV. Eventually one guy came up with an idea: Why don't we take all those Linux USB drivers and make a compat shim to use them on FreeBSD. The interesting part is how he decided to do it; he wrote a compat library that runs the linux USB driver in userspace. The library co-ordinates with a single simple kernel module, cuse4bsd, which creates nodes under /dev and copies data to/from the user space program.
This means the entire linux driver is running only in userspace, where as on Linux it is all running in kernel space. Any bugs in the driver would cause an oops on Linux, whilst on BSD you can simply restart the userspace program containing the driver.
The only kernel code is simple, easier to test and debug, and is the same for all consumers. Compared to the Linux drivers, which are often written by box shifting manufacturers simply by taking an existing driver and tweaking it, and the surface of code within the kernel is tiny.
Obviously, it's not as efficient, data has to be copied. It's a lot safer and resilient.