For me the killer feature is foreign currency transactions with no fees at the MasterCard exchange rate, both online and abroad. My "traditional" bank charges me a flat fee and a percentage for any transactions in other currencies.
$10000 dollars cost £7,867.91
I googled $100 USD to GBP and it comes out as: £7,859.50
Percentage difference: 0.106947%
https://www.mastercard.co.uk/en-gb/consumers/get-support/con...
GBPUSD spot is 0.002% wide (so you’d expect to pay ~0.001% for a single, instant transaction up to several million). It’s not actually too difficult to access this through a brokerage.
That said, if you could really get 0.1% from them it’d probably be considered good at retail.
Is that a good thing?