Very sturdy and love it.  Also perfect that it is modular and can be moved around for individual seating.  Looks better than it does in the picture and very comfortable to sit on because it is firm giving good support to my joints.  
My biggest issue:  I had an experienced carpenter put it together and it was difficult to assemble;  on one end of the side piece which the seat attaches to:  the bolt holes were too large and could not secure that side holding the seat;  he had to cut off a piece of a wood block which I had here and then insert it into the bolt hole and then he was able to successfully insert and tighten the bolt for that side holding the seat.
So now I am very happy with this set which is beautiful on my new condo deck and it’s perfect for curling up with a good book.