Thanks Doug
I wouldn't consider the Panasonic 7-14mm as it isn't that easy to mount filters on it. You can with a special adapter that goes with 130mm filters but it is an expensive route and turns a compact lens into something quite awkward.
Other than the image quality, what surprised me with the OMD and Nikkor 10-24 with Speed Booster was just how easy it was to use. I rarely use auto focus with the 10-24 anyway as I tend to do a lot of pre-dawn or night photography and use a tripod. Even the tiny tripod mount on the Speed Booster worked well, slotting straight into my Arca Swiss style tripod head clamp.
I have written up a review of the Speed Booster on my blog site.
Metabones Speed Booster Review