Bitwala is a good service if you wanna have a visa card, you can use it in any store or just for withdrawing money in an atm, only that you have to convert your btc to usd first, and then you can withdraw it in your atm without any problems. I have been using it for some time and it is a good one.. I use wirex visa card too, i have both of them, but bitwala is the best one from them, because it is more faster and their support replies fast.
So question on that, Anytime I want to use the card I have to convert them first? How long does that actually take in order to transfer? I want something quick and instant, like I go to a bar/dinner/lunch and I want to pull my card out, have it take Bitcoins out and be done with it. I don't want to transfer or wait or anything. Is that even possible?
I guess since you convert your BTC to USD already to fund your bitwala card then it works as what debit/credit/atm card do.
So the answer is yes it will transfer instant just what other cards do, except if there's a maintenance with the platform, tho I don't have any experienced of using them but if you applied a simple logic that will goes like that.