Corner Card is soon going to start a new promotion and will bring you probably up to double of the usual welcome bonus/miles. This information is confirmed but I don't know the exact date. Probably sometime in the next few months.
Regarding the commission: Even if Credit Suisse is charging 2.5% and Corner Bank only 0.9%, you will still find the difference not that big since Credit Suisse is using the Interbanking exchange rate and Corner Bank the Retail Banking rate (slightly higher then interbanking exchange rate)... Therefore you will end up with a lot smaller difference!