Okay, I did a flight into Jeffco (KBJC) since the winds were favoring 30L/R and weather was good. I flew to the NSPYR waypoint, which gives you a rather angled approach to the IF on the ILS, 10 nm from the runway. I was level at 7,000 feet (ALT). I wanted to see how the behavior switching to APPR mode, 30 degrees off the LOC would be and how she would handled the G/S. I don't switch the GPS to NAV, I always use the ILS NAV 2 selector to swap the active NAV frequencies on the GPS instead. That usually gives it a bit of delay, then when the signal is active it switches to NAV for me. I doubt that has anything to do with it though. I always bug up as well to ensure any need to enter HDG doesn't result in a turn. Anyhow, once the ILS was active and switched to green, it turned to align on the LOC and held the altitude, then the G/S came alive and the plane followed it down. I didn't disconnect the AP until around 500 feet, so it worked perfect. I wouldn't expect any more precise capture than what I had.
I am also using the TDS 750 as primary.
