Don,

Here's my Pasadena Fire Department HDR photo. No where near as technically demanding as your night time HDR shot.
Two versions of the same 3 2EV bracketed set:

Name:  _DSC8365_6_7CompressorWeb.jpg
Views: 639
Size:  299.6 KB
Using PhotoMatix's Compressor

Name:  _DSC8365_6_7Enhancer.jpg
Views: 609
Size:  294.8 KB
Using PhotoMatix's Enhancer