On €264,000 you pay 4.75% or 12,540
On €244,000 you pay 4.6% or €11,224
That is a saving of €1316 on an investment of €20,000.
That is 6.6% - a very good return. Go for it. These rates may be increased, so do it asap.
You are probably earning around 5% on your savings, or 4% after DIRT.
So it's costing you around .5% to keep a cash available of €60,000. That's about €300 a year. I doubt if you need to keep the cash available as you are big savers, but the comfort is not costing you much.
As you are well off and as you can handle any short term fall in the stockmarket, I think you should move your cash into low cost unit linked funds. If they rise by 20% over the next year, you will have more money with which to trade up. If they fall by 20%, you will have less money - not really a disaster. Over the long term shares are more likely to rise than fall. As you may be cashing them at any time, then you should make sure to buy shares which have no entry or exit charges.
Brendan