I have a SunRay DX-1 probe for my DFX,i have used it in the early day but in the end took it off and its basically just gathering dust,if you plan on keeping a detector for a long time duration then it could be seen as a good move,one problem that i had was after i switched it to the probe position i forgot to switch it back again into normal detecting mode after pinpointing.Would i buy another one after using a normal hand help probe then my answer would be 'NO'.
The x pointer does have alot of followers but i personally have never used one or plan on buying one either,must admit i like the Garrett PP as my main probe and have my old Whites BullsEye as a backup,have never had any trouble with any of my pinpointers prehaps its because i look after them rather than abuse them.
The x pointer does have some advantages over other probes as it works on the Pulse platform rather than a VLF platform and i would think it would work better in a high mineralized ground conditions better.