The response to this query, if anyone is interested, is that they dont offer a reduced interest rate with the Current Account Mortgage. So a good LTV is not of benefit from the point of view of reducing the rate.
Other things I was told (these were news to me so not 100% sure on them, and they were only points of general interest) were:
The reduced rate (based on good LTV's) is typically, if not exclusively, only available on tracker mortgages. i.e. not available on a standard variable or fixed (though there wouldnt seem to a particular logic underlying this- the basis of lower rate of interest on <60% LTV is, I understood, based on the great security the bank have, therefore the debt can be cheaper to take account of the lower risk)
You cant fix a tracker mortgage at any point during the loan (barring, I suppose, switching out of it altogether).
The other current account mortgage, NIB's offset mortgage, is "not as good", "doesnt have all the features of First Active" - in fairness to the person they acknowledged they didnt have the hard facts on this but the above was the conclusion from a newspaper review of both when NIB's came out.
Any comments on the above appreciated, and any views on whether it would pay to switch to Ulster Bank or others who do give low LTV interest rate. Currently paying 3.29% (price promise of 1.29% above ECB). Must say I like the CAM's peace of mind factor of having built up a reasonable level of funds in the current account and knowing they are instantly accessible, while still always reducing my mortgage - so wouldnt switch unless reasonable level of savings to be had.