I have toured both the north and south over the past couple of years clocking up 3000 miles, without any issues. I reckon the roads in the South are far better than England.
Speed humps are a natural curse everywhere nowadays so you always need to watch where you are going. Some single track roads can be rough like everywhere, but for the most part perfectly manageable.
We travelled Stena Line and the loaders were very sympathetic to Morgan clearance and one was even on his knees to watch us on board. Weather can be variable but the Irish welcome wherever you go is unbeatable.