There is not a huge difference in them in terms of the job they do. OC is less forgiving if your not paying attention, and takes a slightly more deft touch.
The closed comb is a good daily shaver, smoother, not quite as close/feels less aggressive. But I have found almost any blades I have on the good pile work in it. Maybe 20 or so blades, the OC is a little bit more tempremental regarding blade selection, I would probably choose one of maybe 5 blades.
My personal rule of thumb is if I'm keen to use a DE but short of time, not that interested or trying a new blade or soap go for the closed comb. Other than that I tend to use whichever one I put my hand on as both work for me and ultimately do a decent job