Having used many different providers (though not all of the ones on your list), be very careful with suspiciously generous or unmetered anything. More often than not, you'll hit a soft limit where your performance will degrade and/or you'll get kicked for ToS violations.
Most apps never hit those limits, but once you get to multi-thousands/mo in cloud bills, there's benefits in pay-as-you-go billing where the provider is incentivized to let you use as much as you want to pay for.