Sorry Gordon, I didn't realise you were referencing your own situation.
There is no doubt that a, largely tax deductible, current borrowing rate of 0.5% is exceptionally low by any standards, historical or otherwise. That rate could rise of course but, as things stand, it's very cheap money. No doubt about it.
But it's still leverage - it still magnifies all capital gains and losses on the underlying asset. Even if the cost of credit was zero, you are still taking a leveraged bet on the future value of that asset. Whether the value of the underlying asset rises or falls, you still have to meet your loan repayment obligations and you still have to meet all other holding costs relating to that asset.
My point is simply that a leveraged bet on the future value of any asset always carries a higher risk than an unleveraged bet on that asset - regardless of the cost of credit.
I'm not suggesting that this is a particularly profound observation but it often seems to get lost in these conversations. It's always about trading risk for expected return.