Actually, .5 does not parse as a number in Clojure, and does parse as a symbol.
user> .5
CompilerException java.lang.RuntimeException: Unable to resolve symbol: .5 in this context, compiling:(NO_SOURCE_PATH:1)
user> (type '.5)
clojure.lang.Symbol
Interesting, it's not a symbol according to EDN.
Oh yes, there's a few differences. For example, Clojure also has a radix notation for integers (as in 16rFF = 255) that doesn't seem to be a part of EDN. I had assumed that Clojure would cast the deciding vote in these sorts of things, but now that I think about it, maybe not.