I haven't heard of the 87001. All the Eclipse subs. I have seen usually go 881xxx. Where did you see it? What size was it?
The aluminum cone Eclipse subs are good for both SPL and SQ depending on which enclosure and how much power you feed em. I have heard them, they are unbeleivably nice subs all around. And are one of the best looking subs IMO.
The Titanium cone one's are purely SPL. You have to feed them crazy power for them to sound right though. And give them LOTS of air.
I know about the other Eclipse lines but I havent heard the 87001 series yet. I guess they are pretty new. They are below the Alums but above the Polypropylene. They have a aluminum cone like the Alums. I saw them on the Eclipse web site http://www.eclipse-web.com/product/87000/87000.html
They look bad ass and I am sure they sound good. Im going to the local dealers tomorrow to see if they have them. I just want to know what other people think. Here is a pic of the 12" DVC.