Good question - good thread.
Lots of divergant responses, with good reasoning behind them.
For what it's worth, I chose to do my IR on the traditional panel, for the
reasons mentioned by other contributors. I figured it would be easier to
transition from gauges to glass than the other way around, also as a
non-owner there is always a strong possibility that a plane I rent (at
least in the immediate future)would not be glass, so good IFR familiarity
on the traditional panel seemed a must for me. Finally, I figured the
transition from steam to glass meant more dual instruction, and I take that
as an advantage, even if it comes at a cost.

Related question : Autopilot or no. I chose to do my IR without autopilot,
for similar reasons to the above, however I am a strong believer in
autopilots, have studied their use, and consider them to be an important
safety feature in single-pilot IFR. Others aill disagree.