Ubank's is the best savings rate currently available for funds at call, if you are prepared to make the qualifying inward credit of $200 per month.
However, as the AFF article says, "UBank’s “sweep technology” ensures you always have access to money in your transaction account while earning interest on as much of the remaining balance as possible" ... and this is a two-edged sword.
As usual, convenience is the enemy of security. Ubank in their wisdom, and despite multiple postings on their forum by customers requesting an improvement (to which Ubank is deaf), refuse to provide a facility for switching off the automatic "sweep". Therefore you cannot protect yourself by limiting your losses as would normally be able to do by having a small balance in the current account that is vulnerable to loss via criminal activity on the debit card.
If a debit transaction is made that would result in the balance of the current account falling below $100, Ubank will helpfully "sweep" enough funds from your savings account to satisfy the debit transaction. So the thief can happily siphon out your savings, via ATM or purchases, and you can't do anything to prevent them. If you were travelling, had $200K in the savings account, and lost the card without realising it, a thief could have a pretty good time with your card and your savings.
Ubank claim that there are daily limits, and they claim that there are certain protections, but, seriously, who wants to risk having that argument with the bank while you are overseas and a chunk of your savings is already gone ?
My advice is to enjoy the interest rate, and keep the debit cards locked away and not exposed to potential loss; just don't carry them. That's what I do.
The only alternative to protect yourself travelling would be if two individuals A and B with separate Ubank accounts traveled together, then A could have the savings in their Ubank cash management account and leave their debit card at home, and B could keep a minimal Ubank cash management account balance (to prevent potential loss) and, from time to time, A could transfer from their Ubank cash management account to B's.
Or - we live in hope - Ubank's management could recognise the defect in their system design and provide the facility for clients to switch off this "convenient" and insecure sweep facility. (I really don't know what they were thinking.)
Second best, on the face of it, would be ING's "Orange" accounts which have a similar setup - a non interest-bearing current account with debit card, and a linked interest-bearing savings account, paying 2.80% interest if you care to satisfy their monthly criteria which are a bit more irritating than Ubank's. ING has no such automatic sweep, so your loss is limited to the balance in the current account linked to the debit card, which could be $1.
However the question then becomes one of whether you would entrust your savings to ING when the only internet password they will allow you, in Australia, is a numeric-only PIN of a maximum of 4 digits (used as a web password). This is the worst internet logon security of any bank in Australia, and certainly inadequate for protecting $100K of savings. ING rely totally on two-factor authentication via SMS to your mobile, which is a discredited authentication method frequently bypassed by criminals and which the US NIST (National Institute of Standards and Technology) recommend against. As far as I have been able to search, in every other country ING operate in, they allow their customers better logon security than they do in Australia. The 4-digit PIN ING rely on is very easily stolen. I won't detail how, but it's obvious, and their security people must know this. I've tried to tell them and they refuse to allow me to speak to anyone in Info Tech. They, too, are deaf.
Australians always seem to get the rough end of the pineapple.