I only have personal experience with the Oudie/FLARM combination. It worked well for me (past tense - new ship, non-Oudie). Not only does the main display show the other gliders by ID (if you have the proper FLARM config file) but will show an inset box for more urgent alarms.

I generally think that one display for GPS, FLARM, task, etc, etc, information might be optimal for quickly scanning the panel and keeping your head out of the cockpit. However, I can understand that a dedicated FLARM display (with audible alarms) might be better from a safety point of view. I toyed with the separate FLARM display idea but I didn't have the panel real estate so it came to naught.