Personally, they're worse. I've worked with Nextel for about 3 years now. These hybrids are garbage. It's CDMA technology for cell use, but iDEN technology for direct connect (PTT)
The CDMA is from sprint, and it's not that good. The iDEN technology is the best out right now, but it's being phased out by Sprint's CDMA. In 2010 iDEN will be gone and the transformation to an all CDMA network will be complete.