I use Cactus V and PW MiniTT1 & FlexTT5... in addition to old skool ETTL cables. They all sync to 1/1000 at f/2. For the money and ease of use I stick with the Cactus V system. You can add many flashes (I've done up to 5 speedlites) and I have yet to run into any problems. The Cactus V's never fail and I can't say that for the PWs for both the X100s and my Canon gear. Your Yongnuo YN622 should work fine... that leaf shutter is a Strobist dream. I'd also suggest an extra 2 stop ND... you'll then get 2 stop, 3 stop and 5 stop capabilities to extend f/2 work. You will need to make a profile for the internal 3 stop and 2 stop combo to eliminate any cast from stacked filters. Easy though. I also tape a 1/4 CTO gel over the on board flash to help when I go with it alone. Enjoy the new acquire!
My standard street carry...
Awesome little walk around setup you have there. Thanks for the info re setup.
Which ND filter are you using and is it possible for you to post a pic of the CTO gel taped on?
I use a B+W 2 stop... in the image I posted you can see that the onboard flash has the gel on it. Never take it off. Clear taped a 1/4 CTO over the frame. Works wonders. My Flickr page is for family pics and personal work but you can find many photos I took of my son testing out the leaf... also some street work with a single 580exII. After about 4 months I'd have to say it's my go to rig when going minimalist or out to hunt street shots.