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One router knows about 2 paths, the other about 4 paths. Why? Because BGP only advertises the route that is in use. Everyone here of course knows this, I am just pointing it out because culling information before allowing it to be redistributed within your network is what BGP is already doing anyway. It is possible to remove some of that information from the local FIB too without losing anything at all.
Using a default also gives you a dramatically shorter convergence time if one of the transits goes down. Having 800k routes can be harmful to your network even with equipment that can handle it. Yes I am aware that I am not doing what I am preaching here, but I am considering it :-).