Don't get FSX. It will not run well on your computer. In Flight Simulator 2004 the IFR is fine, with all navaids, although UK airspace/ATC is unrealistic. The ATC's a bit underwhelming, giving very wide, obtuse vectors. The ATC does not do anything special for helis. There are some addon programs that resolve the UK issues. Procedurally, though, it's great if you don't need ATC.