Lodging 1 night each Dublin & Belfast

In Belfast we stayed at a Hampton that was walking distance to the train and very central to sights and restaurants. We walked to the Titanic from there.

In Belfast Central Station and Lanyon Place are different stations.
When through train service resumes from Dublin it will no longer serve Lanyon Place station, just Grand Central station.

So that is the better station to be near.

I've stayed at the Hilton Garden Inn in Dublin. Not too far from Connolly.

Thank you all for your help. It is much appreciated!