There is quite a bit on this in another thread on this site? So, maybe you might find some answers there?
In my experience, AIB have been very good about passing on raised rates on a tracker mortgage. They have just been as good in passing down the latest ECB rate cut and my monthly mortgage payment that came out of my account on Mon reflects this (as did the letter that I received in the post last week). They are only obliged to pass on the interest rate cut on a tracker mortgage - on the variable rate mortgage it is at their discretion as to whether/how much they decide to pass on....