Full WiFi signal just means the device has a good connection to the train's computer. It means nothing as to the state of the internet connection. Portlaoise - Templemore is a real trouble location for phones at the best of times.
Mk4/CAF ride is still poor and inconsistent. The science bit
http://www.railusers.ie/passenger_is...cky_trains.php its never been right and its only when the train is on the new track does it calm down.
The ICR/22k has one minor flaw which is an issue on Sligo/Rosslare is in sharp corners at speed it tends to hit the lateral bump stops as the train tries to swing out in the corner. The trusty Mk3 used to do this as well, but the Mk4 doesn't its about the only good thing it has