I used it loads.
If you get a route from your instructor the night before it's really usefull to get on RANT and fly it a few times, (beats flying it in your head) you will notice a big improvment in navigational awareness during the flight wich in turn will give you that little bit more capacity.
There is almost always somthing you'll forget to plan for or account for when training, so best find out what is is when your on the ground and not paying £2 a minute!!!
The lessons are also quite handy but are aimed more at IR training.
It certainly helped me with my IR and would highly recomend it.