On Top.

I use ASA's "On Top" simulator at home. It's not bad, but it's no Elite, at least not as set up on my PC. I bought it a week or two after deciding to do the instrument rating, and it's been a real help for internalising approaches, procedures, and instrument scanning, and generally just seeing what happens when I push this or try that.

Why not use MS FS 2004 or X-Plane? Frankly, because those programs have both too many and too few features. An IFR trainer really doesn't need fanatically-detailed ground texture rendering, but it needs to be able to display and understand every VOR, NDB, ILS, LOC, fix, IAF, FAF, GPS waypoint, etc., in the area you're interested in. It needs to support an interesting variety of programmable instrument failure modes, and a decent repertoire of weather conditions (especially changeable conditions of the sort we simply never see in real life out here on the Left Coast). And it needs to be relatively accurate in flying characteristics, and cope with a yoke rather than a joystick (that's a given for IFR training).

Yes, both X-Plane and MSFS can more-or-less do all this too, but since I run On Top on a slow old laptop that doesn't do much else anymore, I need the stripped-down app. The biggest issue I currently have with On Top is the unrealistic roll and pitch sensitivity -- it's even harder to fly than the Elite, and flying it takes nearly all my concentration at the moment. But so far it's been worth the effort...