paradise is still more on the british side crowd wise while circo loco is more international. it's not as heavy as it used to be (i.e. a few years back paradise was extremely british, now it's more varied).
as for the rest - maybe let the line up decide? or make it depending on what other nights on a monday or wednesday you may wanna go to or 'miss'
It's late September so the only alternative's for our music taste are Pyramid Closing on the Monday, and Dance or Die at Ushuaia on Wednesday (which might be wise as our flight home is Thursday lunch time).
The Paradise line-up is listed and it looks the best of the lot, right up my street and I've never been, unlike Circo which I've been to loads and had some of my best nights in there but it got to the point where it was too rammed to be enjoyable so haven't been for a few years. If Paradise is like that now then regardless of line-ups, I maybe would choose Circo. I'd also add that my wife has never been to DC-10 so really want to take her to one of them so although going to neither is an option, I don't really want to take it.