Some more data points for reference.
8 August
SCB Simply Cash CAD2,847 = HKD17,752.39 (rate of 6.23547).
According to XE.com the rate on 8 August was 6.1068051718.
Spread of 2% and 2% cashback
9 August
SCB Smart card CAD28.35 was HKD173.32 (rate of 6.11358)
XE.com rate for that day was 6.094994
Spread of 0.3 and about 0.4 cashback
10 August
Transferred CAD in HSBC at rate of 6.131867.
XE.com rate was 6.0916
Spread of 0.661 and then cashback of about 0.4%
In summary
- Multi currency cards are pretty good. Didn't get a chance to use the SCB one but is seems spreads were around 0.6 to 0.8 and then you would get a 0.5 cashback.
- With HSBC it seems its better to convert money first rather than just get bank to do the conversion when paying. Converting in advance the spread seems to be around 0.6 while when the bank does it seems to be around 1. Also with HSBC if not enough foreign currency to cover full cost of transaction, they will do the full amount from the HKD account (i.e. 1% spread).
- Normal CC rate is around 2-3% of spread
- SCB Smart card has a very attractive spread, cashback and it seems free withdrawals as well. I think that is a winner for foreign spend.