I used OC. You can apply anything you want over it, but nothing lasts very long. I tried paste waxing half my hood as a comparison to the other side. I'm going to see during my next wash if the paste wax is still there, as the beading is different when all is clean compared to the OC side.
I always apply a spray wax product after washing as it seems to add some gloss and increase beading. Prima Hydro and Optimum Wax seem to be the best from what I used. I have some V7 coming to try and a lot of people say Reload on top of it is nice as well. But for all practical purposes, it seems any long term LSP addition to OC is not going to happen.
OC does bead water and sheet, but it's not crazy tight beads like a carnuba wax. Topping it with one of the products I've mentioned does add additional gloss and bling, but you have to reapply after every wash. It does take some of the fun out of trying new products and new LSP product combinations, but maybe you are not into that. If your looking for low maintenance and good protection then OC is for you. I own two vehicles, one has OC, and one has a wax/sealant combo. It just seems to me, if your going to go through all the prep, might as well use OC, as it does last longer and doesn't require any top ups (like Reload) if you don't want do.