Agreed with posts above. In my system I've experienced larger absolute differences between preamps than amps, so I think you've really got something to look forward to down the road.
Another thought -- sounds like you really like what you're hearing from the Classe, which is great. If you haven't already I'd suggest trying some others before jumping on the Classe. I haven't owned Maggies so others might have some better recommendations on which amps work well with them, but I'll just throw out Bryston or McCormack that might give you somewhat different flavors vs. the Classe (better or worse, that's for you to decide obviously). Also, if it's possible you might go with a tube preamp you might want to pay attention to input impedance to maximize your preamp choices later on. Best of luck in your search.
Another thought -- sounds like you really like what you're hearing from the Classe, which is great. If you haven't already I'd suggest trying some others before jumping on the Classe. I haven't owned Maggies so others might have some better recommendations on which amps work well with them, but I'll just throw out Bryston or McCormack that might give you somewhat different flavors vs. the Classe (better or worse, that's for you to decide obviously). Also, if it's possible you might go with a tube preamp you might want to pay attention to input impedance to maximize your preamp choices later on. Best of luck in your search.