Eclipse is the shit....very expensive nonetheless...they are expensive cuz of their build quality (which is impeccable).
Old Alpine decks are alot better then the news ones...then again thats IMO cuz I'm not fond of any alpine product other then the amps and flip out monitor....
The only thing bad i have to say about Eclipse is that they dont provide as many features as lets say a top level Pioneer deck (6300 and up). Which is why i think a brand like Pioneer could be an alternative to an Eclipse deck.
I have the 5504 by the way. Ran me about 500 bucks.