I transitioned to glass after about 1000 hrs and learning to fly in a Cub. I did my homework with the manual and a simulator, so the G1000 transition was painless. In fact, I combined it with my multi training, and got the Commercial AMEL in 10 hrs, so going from steam->glass was straightforward, at least for me.

Then after flying only glass for awhile, I did an instrument proficiency check in a steam gauge airplane. I did OK, but I really had to work at it.

My thought when I finished that IPC was "Hmm...if I had never flown on steam gauges before, this would've ended poorly."

If someone gets his instrument training in glass, should s/he be allowed to fly IMC on steam gauges without further training? Right now the regs are mute on this, but I wonder if it'll stay that way.