One of the things that makes french pastry so good is the buttery taste. You can have good pastry without butter but it's definitely not on par with a proper butter croissant.
I was never a butter guy, i don't like it when food tastes buttery. I tried vegan butter, and i was pretty shocked how much it smelled like butter. I don't know how well that translates to baking and such tho.
I haven't tried vegan butter yet, it's easier to find margarine around here, which tastes like ass most of the time. But I'd definitely give it a try if they manage to get the buttery taste without the suffering.
The weirdest part is that i absolutely dislike coconut, which sucks, and it's on a coconut base, but tastes more like ice cream butter? Hard to explain