My recommendation is that you pick a bank that you have an established relationship with as your experience will be completely different depending on what branch structure you are operating out of.
As an example, I went with ulster bank in baggot st when starting my business back in late 06. Had a terrible time with them, constant requests for documentation "because their forms had changed since I subitted original docs", no responses to emails/phone calls, no account statements for over 14 months despite it being raised as a serious issue, no credit card option etc etc. Sorry Rant over
I spoke to my (small) personal BOI branch which is in Cork and got up an running with them in about 1 month, credit and laser cards issued, minimal paperwork and no fees for two years. Closed down ulster bank
However it is quite plausible that the same experience would have been had if I was dealing with BOI baggot st instead of UB baggot st and had previously an existing relationship with a small UB branch in Cork.
So, in a long winded way, I am saying that it is all about the people you are dealing with, rather than the brand of the bank. My suggestion is if you can go with a reasonably small (but secure) branch that you can easily build up relationships, do this rather than to one of the big Dublin branches.
I would recommend BOI as the account setup was much more straightforward than UB, but I think building a personal relationship with the people in the branch is the most important element.