I'm guessing the output is somewhere in the 250-300lm range, based on ceiling-bounce comparisons with other lights I own that are rated at that brightness, but I don't have the equipment to measure its brightness objectively.
If I had it to do again, I'd try to come up with a more elegant way to connect the driver to the LED assembly. I may yet go back and modify the connection to use a barrel plug and socket, so when I screw the driver pill into place, the plug and socket line-up and automatically make a connection. But it's not like I'm going to be disassembling this light on a regular basis, so I may also decide to leave it as-is because it's not a big deal.