Well I went with the Z2 and my H3 is still in the installation shop. Apparently they ran into a problem with the onstar/chime interface. They think it may me a faulty piece. I hope that is all it is and not something to do with the compatability of my truck.

I know that Hummer switched from Class-2 Bus to LAN. And mine is LAN. Not sure what either is though, or if this will pose a problem,

All the H3's are class 2 bus. They use the same interfaces as the 03-07 H2's. The Per GMAH24B workes well.

What problems we're you having?

The 2007 models, the later production ones, from what I was told changed from BUS to LAN

The 07 NBS Silverado, Tahoe, Suburban, Yukon, Yukon XL, Escalade and the 08 H2 are now LAN. The H3 has stayed Class 2 Bus. Have done two H3's this week. An AVIC-Z2 in a 07 H3 and an AVIC-D3 in a 06 H3.