I like my H3 too. It's my first GM vehicle but not my first US made vehicle.
Today is the first I have heard of people having it (rough idle, check engine light, and engine misfire code) happen a second time and this worries me about the fix.
If it is a recall issue they should let us know ASAP and treat all H3 owners the same and offer an extended warranty and guarantee the head replacement.
Replacing a cylinder head isn't rocket science and it shouldn't take a week to complete the job. I don't want them to rush it but a week is too long. I also worry about non-head related complications after the head replacement like oil leaks, timing chain issues, camshaft etc.
I bought a new vehicle to avoid this kind of stuff and never thought I'd have a head replacement at this time!
More info here...
http://www.hummerforums.com/m_31906/tm.htm