For years I had been waiting for a system that I could adjust the power of my lights from camera position. This year I got that system, it is great to be able to change the power from camera position - but not as great as what I thought. But yet really nice. The one really thing I didn't expect a company was to produce a system where you could use the same flashes and strobes with different brands of cameras, and only have to change the transmitter and still have the benefits of TTL and changing power levels. Last week I had to pull out my Nikon gear and it was great using the same lighting system as what I use the OM-Ds! Here are some minor nitpics you might want to keep in mind if you are trying to decide on what to get. I called this is a system as the comments address the TT600, TT685, V850II, V860II, and AD 200 - Flash zoom setting are not accurate. - These units use two different sizes of sync cables, 2.5mm and 3.5mm. - Only a couple of units have the capability slave groups being set to D or E. The TT600, V850II and the AD200. - Three different control layouts on different flashes, one for the manual flashes, another for the TTL flashes, and another for the AD200. - The AD200 controls are virtually unreadable when in full sun. I made a sunhood for mine. But I guess the answer for this is just to depend on the transmitter. So far it has been a great system.