Fright Level,
I do agree with you, however Tolka asked about..
software for practicing radio navigation and instrument procedures
I have found that RANT allows one to practise and become familiar with the procedural element of instrument navigation with out getting caught up in the drama of trying to fly an unrealistic flight sim at the same time. I think flight sims like MS are fun but not serious enough.
Flying an ILS is quite straight forward compared to flying an NDB approach with the beacon on the FAT (Cranfield) when the mind has to deal with needle 'reversal'.
Joining an NDB hold needs thought and sometimes quick thinking, these type of things are easier to practice without the distraction of 'flying the 'plane'.
The real advantage of RANT is that you can stop at any time and also re run the fun with traces plots etc to see what happened.
Pays yer money and takes yer choice I s'pose
UTF