Just did a few calculations on the value of this deal to someone with an investment mortgage and a tracker of 0.8% above ECB using Brendan's link
http://www.loanclc.com/
€100,000 outstanding with 11.5 years to run.
Total repayments = €110,781
Pay €5,000 off mortgage and get €500 credit from PTSB.
Total Repayments = €104,688
Saving €6093 in total repayments - but this has cost you €5,000 to benefit by €1093 over 11.5 years.
Factor in the reduction in interest & the subsequent rise in tax of €497 over the 11.5 years (assuming no changes in the tax regime for landlords).
Factor in having my €5,000 available to me with a small interest accruing (let's say 2% p.a less DIRT) each year which would give me €866 in interest over 11.5 years from this link
http://www.moneychimp.com/calculator/compound_interest_calculator.htm
€497 + €866 = €1363 v €1093 (saving from PTSB deal)
So in this case a landlord would be worse off by taking this offer.
These calculations assume that interest rates stay at the current rate over the 11.5 years. Of course this won't actually be the case.
With ECB rates at 2.00% the deal would save €1440 but would cost €700 in lost tax relief & €866 in interest = €1566.
With ECB rates at 3.00% the deal would save €1798 but would cost €914 in lost tax relief & €866 in interest = €1780.
So I think the ECB interest rates would have to be over 3.00% for the full 11.5 years before there would begin to be any advantage at all to taking the deal for an investment mortgage holder. At what point it becomes an advantage to tie up €5,000 is debatable. The ECB rate would have to be 6.00% over the full 11.5 years to gain €373 by paying off €5,000 and that's assuming that the saving interest rate stays at 2% less DIRT.
So whatever about this possibly being a good deal for home owners - I just don't see the advantage for an investment mortgage holder (the caveat being the figures that I have used).