The overall quality of the item appears to be solid. It isn't exceptional, but it is pretty good for the money.
The assembly is fairly minimal, but use caution when tightening the fasteners for the legs. There is no hard stop when tightening. You have to use judgment to figure out when tight is tight enough or you could easily damage the legs. There are no written instructions in English, so that could be improved, but there are only 8 screws and washers for the legs to deal with.
After assembly, I found the butterfly leaf to be smooth and quiet in operation. There is a nice hinge, no rubbing of the wood in motion, and pads are present to prevent wood on wood contact. Extending/retracting the table was a pretty smooth/easy process as well. The finish of the wood is decent and smooth, though I would prefer it be a bit thicker for extra protection (preference). There are levelers on the legs, but I chose not to use them on hard floors as they are a bit small in diameter (better for carpet). I used felt pads.
The table top has a little bit of play from the extension rails, but this isn't noticeable unless you press down firmly on a corner. The oak wood and grain look nice, and the table has a simple design with a mid-century touch given the round, tapered legs. The beveled edges of the top are well done.
I'm pretty happy with this table and hope it holds up well over time.