Haha, when I first saw "Bolt" I thought "Hey that's a CardConnect thing!" because I've integrated with it before and will be using Card Connect's Bolt again for this project. I scoured the Card Connect website to make sure it wasn't some kind of partnership and it's not the same thing (not saying you said it was or thought it was, I thought it might be at first).
I can say that Bolt is pretty easy to work with from my experience. I have a wired Bolt reader (IPP320) sitting next to me as I type this (I've worked with it through my employer) and a wireless/BT VP3300 in my bag (which is what I'm going to use for my food festival stuff).
Nothing beats Stripe's docs and the community around it (both in info/SO-answers and in things like SDKs) but CardConnect and Bolt are easy enough. That said I wish their onboarding was streamlined. I had to be in 4-5 meetings with them before I got credentials to start coding and I'll have to be in a few more before I go live. I think you can use their UAT or similar without an account but I wanted to make sure they'd accept me before I started working on it. Super nice people, it just doesn't compare to a few clicks with Stripe and boom, you are off to the races.
* JS/Web tokenization (via iframe + postmessage)
* iOS/Android SDK to work with an array of in-person readers
* Apple and Google Pay support
* And then all the API endpoints to charge a card, create a customer, etc that you would expect
[0] https://cardconnect.com/