I've recently used XP2 and developed it in Diafine. The results came out better than expected. It's the only roll of film I had at the time and wanted to test a camera I had just received via eBay. There was a 14 day return period and I wanted to test right away. I read somewhere that XP2 can be developed in Diafine (or any other b/w developer) in addition to regular C41 processing.