Well, I don't personally have an ezOSD, but that was my second choice after the Skylark. I was a little unsure about the ezOSD because for a while a lot of people reported that it took a looooong time to get a satellite lock, but lately I haven't seen that stated as much, and many people seem to be reporting that the satellite lock isn't bad at all.
I think if you have an Immersion video TX there is something to be said about the ezOSD having a direct cable connect to the TX, but if you are going to have to solder anyway, the Skylark is probably an equally good choice. Only real consideration is that Skylark has three separate modules (OSD, current sensor, GPS), while ezOSD has two (current sensor, and OSD/GPS in one). So in the end the Skylark is a little easier to fit into the shell; the ezOSD will fit but the main unit is a little bulky.
All that said, the "rumor" is that DJI is coming out with a Y-cable that will let you plug their iOSD into the main board, so you may want to sit tight a few weeks and see what happens.