I trained on steam gauges, and flew G1000 in a DA40. The transition is not that obvious, many reflexes have to be re-trained.
I'm not surprised that FTOs have better pass rates, but I don't think a glass cockpit makes the IFR training shorter or easier - it's just another way of presenting the same problems (ok, I trained in a Bonanza with dual GNS430, RMI and HSI...).
Moving from dial to speed and altitude tapes for example is not that easy. Where flying x'000 ft means "keep the needle vertical" on a classical altimeter, it's not the same with a glass cockpit. This is where a smart us of the bugs can help a lot.
I wrote several posts on my blog about my G1000 conversion. A good starting point to read about that is
http://www.plasticpilot.net/blog/tag/g1000/
And by the way, Cirrus is now offering the G1000 as well, in the so-called "Cirrus perspective". Note also that Avidyne system is not as integrated as the G1000, as it does not include the radios. This is a different approach, with different failure modes. Please, I did not said any is better than the other.