Update. I just gave the Endeavor a try on the trip up to the shop. It did a little better than the Brake Boss, but not good enough. I especially didn't like having to go through the button sequence to adjust the boost while driving so after a couple calls to the distributer I bought it from they agreed to credit me the money I spent on the Hayes, & I replaced it with a Tekonsha P3 for an extra $24.00. Its installed now, & I'm waiting for my 5'er to be done then I'll adjust it, & see how it works in comparison. I'll let you all know how it goes. Thanks for all the advice.