'Overhere', none of these units are approved for IFR, although for some reason they seem to have IFR waypoints (even the RNAV ones - which is a bit of a worry if anyone is stoopid enough to try and use them for an approach.)
Wheeler - I have a TSO'd GNS430 in the panel, but if I was stuck I would not hesitate to use my GPSMap296 to fly a GPS/RNAV Approach.
FTDK