This. Round-gauges require you to build a better mental map of where the airplane is in space. The skill of developing a scan is very important. I've seen lots of people fall apart transitioning to round-gauges in IFR when they learned on a G1000. Going the opposite way, the results are completely opposite, I've never seen anyone encounter significant difficulty transitioning to a G1000 system, apart from learning the critical switch-ology, but that's system dependent and varies with whatever glass system you have (rockwell, chelton, honeywell, garmin, etc.). It's also relatively easy to learn with exposure. Trying to help someone that is struggling in a round-gauge cockpit means going back to fundamentals of instrument flight.