is slider hitch really needed with standard box? (6'5")

I have a slider, but have not used it in 5 years of towing our 5ver because of its front cap design. The rig has been to 90 degrees, as I had the dealership show me it could be done without using the slider.

I still had them install one, just to be safer....someday, I may need it. I also have a blue ox bed saver, for the same reason, I hope I never need it, but its there just in case.