Hi TheSkiingPilot,
I just returned from Dublin and the technical interview lasted about 30 minutes.
It was with an old Ryanair captain and he really went into details about jet engines, navigation systems, like INS/IRS, anti/de-icing systems and rhumb lines/great circles. Other people were asked about electrical and hydraulic systems.
I've practiced and prepared my technical interview with the Ryanair interview package at latestpilotinterviews.com
This was a good preparation and the questions were accurate.
The simulator was not too hard and is mostly about CRM.
Good luck if you're attending the assessment.