Looks excellent and comfortable to seat on.
One comment: when you attach sides to the backrest, turn the chair on it's feet to make sure it is levelled and not rickety. It will be difficult to assemble the seat if these parts are not levelled. Also, it help to have an extra hand for a seat assembly as I found it is difficult to pull the parts together to bring the holes to the same level  and to use Allen key at once.