We had the original style sg 16k for the last 4.5 years until upgrading to the new style sg 18k. The difference in the newer hitches is amazing. All of the steel is thicker and better designed. The reason I mention this is that recently the 16k had become very unreliable with multiple weld failures and cracking within the main body. Called pullam on it and they simply offered to sell replacement parts. The warranty is only a few years OR 30k miles whichever comes first.
They are great hitches but all the moving parts does come with a price. The newer style are significantly more robust than earlier generations.