After just a day with my Leica D-Lux (Type 109), I’ve found features most of the online reviews missed, and discovered things I thought would be there which aren’t.
I’m sure you know about the 4/3 sensor, 4K video, dial controls…
No remote flash support
Look, I doubt I’d have used it much, but if the Type 109 supports remote flash, I can’t work it out. Mind you, the included strobe is so gutless it probably won’t actually add to the exposure much if you use it to trigger slave units though.
A lens shutter
There’s effectively a pair of shutters in the LX100/109 – a mechanical leaf or lens shutter, and an electronic shutter. This means flash sync up to 1/4000th of a second, which is really cool when doing fill flash outdoors. It works to 60 seconds.
The electronic shutter will take the exposure to as short as 1/16,000th of a second, which I want to try Real Soon Now – that’s studio flash duration style stuff, and will result is some stunning images. By people better at this stuff than me.
Nigel Paterson - 0410878752 
I’m pretty sure it supports remote flash since the LX100 supports it. It does a great job at it too. You need to put the little flash on the camera first to unlock the Flash menu item (which is on page 5/7 of the Camera menu). From there, you can go on Page 2/3 of the Flash Submenu and put Wireless to ON. If you have any problem, send me an email and I’ll try to help.
Maybe I tried to find the menu without a flash attached. I thought I’d read it was capable of remote flash, hence my comments about not being able to get it to work. I’ll do a bit more research.