Hi Cookiemum,
Did a comparison of several insurance companies + HSBC, and HSBC's coverage stands in the "middle;" not too good, not too bad. One of the problems with bank insurances is that there is no one particular person who will follow your account, in any case when you need him/her. It's just a hot line, in which you will have to press "1" for this and press "2" for that.
Eventually, I opted for Manulife for my 4 month old baby.
You will have to prioritize what is most important in their list of coverages. I opted for daily room/board, which will practically be required every time you are hospitalized, whether it be with surgery or not.
Hope this will help.