I've never played one, but I did have a conversation with them via email last year when I planned to have a custom built. I didn't order, there were a few reasons for that...
First of all, their responses took forever. If i remember correctly there were weeks until I got answers to some questions. I understand they're growing in popularity and have tons of questions every day. But it doesn't feel comfortable to start a build and know that they may not read my emails for weeks, especially if it's about making changes or about some other important stuff. I also noticed other people complaining on their Facebook about this.
Secondly, I'm fine with they having predetermined body/headstock shapes and you can't order anything outside of those. But I wanted some other customizations for the neck, like nut width, thickness of neck and fret board radius. It was not that i asked for something really weird or out of the ordinary, but they just wouldn't do it. Options were written in stone. That's not what I'd call Custom?
They basically told me if i like their guitars sound and appearance I should trust that they know what they're doing, otherwise I need to buy from somewhere else.
But I'm sure they're good guitars, so if you are happy with the options they already have you'll be fine. But if I were you I'd shoot them a few emails asking questions, you'll get a feeling for their interest in their answers and how fast answers arrive.