I can't remember exactly, but I thought 1-2 hrs was way light. I was going to do mine but decided against after seeing some instructions.
Check this out... http://www.scottwinger.com/2001-engine.html
I would say it definately took me longer than 1-2 hours to remove mine and replace my valve cover gaskets on my old 99. Probably 4-5 hours.
I didn't remove the upper intake, but did have to remove the a/c refrigerant so that I could remove the passenger side valve cover easier. The passenger side v/c is cake, doing the driver side was the pain in my ass.
This was my first time ever working on any Cobra though, so I imagine I could do it much faster my 2nd time around