kernel versions..

which is the version you would use by default on older equipment? why?
newer equipment? why?

would you ever go as far back as the 2.0 kernel?
or would you say that the loss of reliable threading prior to 2.4 is a show stopper?

what about building the system, with a 2.2 kernel?
patching the threaded process code to gain the 2.6 functionality in threading?