Hi Fran
I started this post when we were thinking of switching to KBC. We went ahead with it and recently paid our first mortgage repayment to KBC, which was 100e lower than our monthly payment to Bank of Ireland. With regards to your query above, we didn't have costs anywhere near €1000. KBC offered us €1000 to cover our legal fees and we got half price home insurance with them. Our solicitor cost less than 1100e and we had to pay 127e for a valuation. So, it was nearly break even by the time we got the 1K back from KBC and took up their offer of home insurance. You do need a bit of cash flow though as the 1000K from KBC is provided within 30 days of the mortgage draw-down.
I know that there is a a bit of hassle doing the paperwork but when you add up the savings they are very good. I work in the public sector and haven't seen a salary increase for quite a while, so I consider 100e extra a month in my account quite a good payback for a bit of paperwork