Yes, I used RANT throughout my IMC training, and found it extremely useful.
RANT XL is, presumably, a more recent, enhanced version.
RANT allows you to concentrate on the navigational instruments, and you can customise the panel fit. You can see what you're doing against either a VFR-type map, or against an IFR-type chart (not to be used for real-life navigation!), and there are also samples of approach plates to suit the airfields included in the package.
I have not stopped using it since gaining the IMCR a year ago - it is still very useful for practice away from the aircraft.