As some have pointed out exactly what Quattro and I assume the reqular 5 and not the 5A.
But I think the following can be said: The built in "subs" of the 5s are better than the Quattros. I think the 5s 7 inch bass/low mid driver is better than whats used in the basic quattro. Does even the best Quattro use that driver at this point? I also think the cabinet of the 5 performs better than that of the Quattro.
700 bucks matters, but I think it does get you more if you can swing it. Also as pointed out, size of room could be a significant factor. Another thing, find out how old the 5s are, they have been in production for a quite a while. I believe they have had various small improvements over the years with no model change.
TD