When I got my J-Station, one of my bandmates at the time had the POD 2.0. We compared the units and found that the J-station was better in most areas, with the exception of the compressor. I think the units of the time sounded best with the speaker simulation off and into the effects return of an amp though. Cabinet emulation has historically been and continues to be a weak spot in many of the digital modelers. The Line 6 POD 2.0 won the marketing war. I also owned a Behringer V-Amp 2, which seemed like a blatant clone of the POD 2.0 and I also owned the Vox Tonelab LE which sounded pretty decent. I heard from a former Line 6 employee who worked during that period that Vox licensed the POD 2.0 modeling for the tonelabs. The POD XT bean replaced my J-station for direct recording, but honestly the tones were not much improved.
The johnson stuff seemed to be better than its competitors though and I think that much of what they did was rolled into the Digitech Genesis modeler and the later GSP1101. I need to see if I can find my J-station and try it with an IR loader to see how it fares.