I think it is about the market rate BLR-2.x%, unless you can go fixed rate. The bank even offer 2 generation loan, mean you got the loan for yourself and commit on behalf of your children, so your children will serve the loan when you die.
When you pass the last word to your offspring, "Dad got nothing left for you, just some watches, some pre-owned from the Uncle in MWF
and of course follow with huge debt, please pay on time, otherwise this house will be lelong...Good Luck kids"
So it is better clear the principal when you have extra $$$$, but then no more extra $$$ for this hobby, a dilemma indeed...
Just my 39 cents