best Windows XP software for RX100 RAW processing?

I'm new to the RX100 and to this forum, so sorry if this has been asked before. I did try the forum search and did not see anything current and comprehensive.

I have read in this forum that RX100 RAW files do have noticeably better detail than JPEGs, so I would like to try RAW mode. I already own Lightroom 3 and Photoshop, but Lightroom 3 does not handle RX100 RAW files and Lightroom 4 does not run on Windows XP. For you Windows XP owners, what software do you use to develop RX100 RAW files?

I have tried Sony's free "Image Data Converter", which does run on my computer, but seems really clunky. Adobe's DNG Converter also works fine and seems to be easier to use with Lightroom 3. Has anyone tried to compare these 2 for the quality of the output?

Also how does DXO compare to these? Price for that is $169. Is it worth it?

Thanks for your advice.