Hi CharlieDeltaUK,
I used M/S Flight Sim briefly, but like you felt it was likely to take too much time to master the software before it was going to yield much training value. It was good for practicing basic accurate flying however; (i.e. maintaining altitude, airspeed and heading within limits).
One package you will definitely find useful, if you don't already have it, is Oddsoft's RANT XL. [
http://www.oddsoft.co.uk/] I believe the latest release of RANT is still Release 3.
I have heard that XPlane is also useful, but have no experience of it. Perhaps other contributors can comment.
Regards,
BP.