OBD II scan tools

Hi,

Have any of you purchased an OBD II scan tool (PC based or otherwise) to aid in diagnosing problems. I am looking at several different versions and am having a hard time choosing one.
I want to have access to the GM extended data set and be able to monitor data in real-time so I am not interested in a code reader only.

If anyone would share their experiences/comments on a model it would sure help.

Thanks,
Paul.

I have an AutoXray Ez-Scan 6000, it will scan about everything(except pre-1996 imports). Most of the problems with any scanner can be fixed with software upgrades and most have their glitches, my autoxray displays a false value for tcc slippage and won't show cam retard on a 98(defintely needed when replacing a distributor) and from what I hear the AutoTap software won't show the correct value for cam retard on V6's, but that could all change with a new software release. My scanner has the 8 line display unlike the older autoxray 2 line display. You may be able to find one of the older models for sale on ebay or buy direct from autoxray.

Thanks for the info Jeremy.

I'll look into the AutoXray. AutoTap was one model I was considering as well.