Speaking as a new IFR student just starting out, I don't really want to use
a computer to learn to fly by reference to instruments. I'd rather do that
in an airplane. What I want help with is learning all the procedural stuff
and developing my situational awareness, so I'm not trying to learn how to
interpret a pair of VORs and NDB at $130 an hour. I don't think the lower
flight model quality is an issue there.

You have it backwards actually. Doing it in the real airplane is
a LOT more expensive and you have a LOT more to deal with. Doing it
on the simulator, you can focus on only the basic attitude isntrument
flying and nothing else. Doing the situational awareness in the plane
is a waste. Just about anyone (well almost) can navigate from a point
to a point. Do you really want to be flying along an airway picking
out the cross-radials every 20 miles and spending $35 for each
intersection? Do that on a computer where you can jump from point
to point in a matter of seconds. In fact, online there are many
models that do this. When you get into the plane you want to
be proficient at all the very basic stuff and semi-proficient at
the more than basic stuff. The simulator is more difficult in some
ways but early on when you screw up more than other times, the simulator
makes it very convenient and far cheaper to restart. In the
airplane getting back into position to re-start a maneuver can cost
a lot of money quickly.

Gerald