First and foremost!
It's really a personal choice, but realize that there are thousands of people out there that are towing a 5er on a shortbed without a slider. There are also many people out there that are towing a 5er with a slider that have never slid it except for the first time to make sure it would.
The biggest thing is to know the limitations and never exceed them. If you can turn 80º never turn more than 75º and you'll be fine. If it takes and extra pull forward to straighten out to get into a spot without jack-knifing then do it.