2) No fees using any ATM to withdraw cash (AKAIK when I asked the Mondo guys)
3) Instant notifications when you make a purchase and the ability to switch on and switch off the card. So you're never blocked when you purchase Christmas presents and weirdly spend more one week.
4) They have a nicer app that helps you track how you're spending and your habits are changing. They've even managed to put in logos for each merchant. I know that's hard because I've done it for my startup -(for example a mom and pop pharmacy)
5) Easy integration into transferwise and other apps where you can get loans from banks in a marketplace so you get the best deal. In general there's a whole lot of benefits to the APIification mondo offers. It avoids doing what everyone does by just sending you off and integrating with others who do something better.. Credit Cards? Loans? FX transfers. While I don't know the details this is what I got from their marketplace vision.
6) Sign up using something like Jumio, or Jumio? (Not sure i don't have Mondo, wish I did- so if you're reading this give it to me!) so it takes 30 seconds and no need to visit a branch.
Ultimately its your choice but they have a pretty cool thing they're building.
I might want to point out I have nothing to do with Mondo. I love their idea but the way you asked that question suggests I may be implying that, but I don't have anything to do with them.