I've got about equal time instructing primary students (Air Force UPT students, that is) in both the T-37 (OLD, OLD gauges) and the T-6 (glass system-- probably not as nice as the G1000, though). I've also got a couple thousand hours in the KC-135, with various different versions of avionics, (mostly glass cockpits, though).
I think that there are some definite advantages to either system... but at the same time, I think that beginner instrument training should either be done with the steam gauges, or with most of the nicer features of the glass system disabled. It seems that with a moving map display constantly available to the student, they tend not learn any of the other tools for maintaining SA. The moving maps are great... so great, that it is very tempting to rely on them exclusively. When I used to turn off the map mode, many students would be totally lost despite having a bearing pointer, full electronic HSI with two course needles, a DME and a distance to a GPS waypoint all available.
These features are great, but there are certain skills that every instrument pilot should acquire. These include intercepting courses and radials, turning from radials to arcs, and vice versa, identifying ones' position based on basic NAVAID information, keeping track of one's position during an approach, etc. Also, I've noticed that people tend to have less difficulty moving up the technology ladder than down it (although your results may vary!)
As for autopilots, they're great, especially for long duration sorties. I can't imagine flying a 10 hour plus sortie for example, without one, even with 2 pilots aboard. Well, I guess I can imagine it, but it would be a royal pain. Still, managing the automation is a separate skill that needs to be learned. For example, when the autopilot makes a turn that it "shouldn't" have, it can be tempting to try to correct the situation by reprogramming it rather than turning it off and hand-flying the correction first. And since the pilot hand-flying the airplane is the ultimate back-up to these systems, autopilots are another feature that fledgling instrument pilots should do without until they've developed good basic skills.