Eclipse is owned by Fujitsu, who makes the Toy and Lexus HU's. Eclipse was the brand they came out with about 15 years ago when they realized no one would buy a $1300 CD player called "Fujitsu Ten" : )
Great sounding HUs, the single DIN units got too "Tokyo-by-night" for my taste this year, but the 2-DIN units are cleaner in design and I think have a better UI than the Pioneer.
The Pioneer also has lower end D/A converter ICs, and a 2V preamp out. The Eclipse has a 5V out and 24-bit D/A conversion. They even give a 3-year warranty when dealer installed. And I beleive you can change destinations and such while driving (the Pioneer has a US-only FW version that prevents watching video while driving, which is fine, but it also prevents you from using many nav features while moving, which is a PITA. The unit knows you're moving from the internal gyros - this is not "foolable" by the installer through wiring. It can be fooled by a mod to the Pioneer unit, but it voids the warranty, so I'm not hip to that).
http://www.eclipse-web.com/avn/avn5435.html