The Amex Centurion lounge is usually rammed (and an odd, elongated shape that makes most of it feel like a corridor) but I imagine at some point in the day when it opens it isn't too bad.
Otherwise the Flagship lounge in D is excellent (which you will be able to access) with nice views and the AAdmirals clubs in each terminal are perfectly "serviceable", let's just say!
You are fine to hop around any of the terminals, you could even post a DFW skytrain/lounge-hop although you might lose the will to live/fly....