Very comfortable, the waist belt may be a little highly situated but not uncomfortable, the buttons are a little difficult to do up because of the style & the extra threads in the button holes but if you can deal with slightly finnicky buttons it's fine :) About half the buttons are hidden ones which lessens the amount of finnicky buttons.
I'm planning on getting this set-up in a different colourway for my next jirai dress to be honest
I don't know what customer service is like as I didn't have to contact them, shipping felt a little expensive compared to other online shops but it's nothing unexpected for where this is actually coming from ^^