I have installed an x20 system in my house and I have a few blinds spots.  I do not need 3 more decos and finding a single x20 is about as costly as buying the x60s.  I was wondering 1) will the x20 and x60 play nice?  2) do I get any advantage if I use either the x20 as the primary or the x60?

Thanks.

Odie.