Hi all. I received the KX-800 a few days ago and so far I've really, really enjoyed it. Before I've used a Metz 24 attached to the Pentax 100mm macro's lens hood with a DIY concave diffuser (see OrionMystery's site for more about that

). Now, I'm not big on technicalities such as guide numbers etcetera - I tend to use what I have and try and make the best of it.
For me, portability is key. Lugging an insane bracket robot around the woods is a no go, and that's what made me get the Metz 24. I still love it! The KX-800 is an entirely different beast. With the 100mm the flash arms/tentacles are maybe even a bit too long for my liking, although they do make for some really cool backlight/rimlight stuff. One flash facing forward at the subject, one higher up and behind the subject. Sweet..
The flash arms are STIFF. Holy crap. The joint pieces are soft rubbery plastic so I'm guessing the friction will stay as it is for quite long. The're also very lightweight so it doesn't throw the rig off balance. Adding some DIY diffusers on the flashes isn't a problem. They'll stay put just fine. Needless to say they wiggle a tiny bit if you shake the camera, which is a given. I love how I can adjust the lighting on-spot and quickly. The LED focusing light could be 1/5 the size and It sort of looks like a reading light. The focus light arm is also a bit less flexible and a bit cumbersome. However, it's a nice thing to have and definitely better than the velcro attached led torch I've used before

. Even better; you can adjust it so that it faces the same way as your main (front) flash to get an idea of the lighting.
I read someone complain about the battery door.. Come on. It's just fine. Just don't abuse it. Replacing the batteries is nice and quick

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Cons: the KX-800 doesn't fold into a compact, nice package you can fit into any camera bag, and I'd avoid bending the arms too much. It needs some protection around it while traveling. Also the hotshoe piece is a bit too loose and you need to tighten it up quite a lot to make sure it stays connected. At first I thought my K-3 II and/or the KX-800 didn't communicate properly but then realized the hotshoe part is a tiny bit smaller than the Metz 24's, for example. The Metz 24 needs some force to even slide in whereas the KX-800 has barely any friction. This is still a very minor issue

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I'll post some pictures when I get back home from the cabin I'm in now! So far I'm loving this weird octopus/alien flash. And their customer service is very good too!