with the discounts I got with the Dougs and free shipping I saved about 500, straight from the website on average day TTis around 150 more, not knocking the TTis, them and Dougs seem to be the top ones and comments both ways about either set
When I was looking at the headers I saw the slip tube for the TTis, never saw any negative comments about it but it did seem weird to me as I never seen it before, I can definitley see where it would make an install easier, especially if your working on the floor