According to the manufacturer, the specs. are as follows: 11.5 ft. in length (I measured it at an inch or two shorter), 25" wide (I measured it about an inch narrower), weight of 50 lbs. (did not verify), depth of 13", cockpit 17" x 34", max. capacity of 250 lbs., polylink3 material. It has a rubber oval hatch cover in the stern with a foam bulkhead behind the seat (hinged hard plastic seat with padded coverings). I believe it was categorized as a "day-touring" kayak. It is also equipped with the nice foot braces.
I have only used it a few times myself. While there is ample space in the rear hatch, there is no forward bulkhead (or hatch) so proper flotation must be used for safety purposes. At 150 lbs. myself, it is a fairly tight fit. There is plenty of room on the seat itself, but my legs account for all of the space up to the footpegs as the width narrows rapidly toward the bow direction.
Our daughter would probably rate the Sonnet a 10+ as I believe this kayak was designed for people like her. She is rather petite and much lighter than I. She zips around in it forward and backward (even while sitting on the deck behind the seat). Of course she also loves it because it has a flowery design stenciled on the bow deck. Oh, she also likes that the cockpit coaming on the sides are lowered so it allows for more clearance when paddling.