If you are not concerned about opening the rear door it really doesn't matter, the most important thing is to make sure you choose a bike carrier that works for your bikes.
If you want to be able to open the back door of your pickup we would recommend the Atera Strada DL3. This bike carrier slides away from the back of the vehicle, rather than just tilting, so you can be sure you'll have plenty of space to fully open your back door. Most standard tilting racks won't give you enough space to open the back door.
The Strada DL3 is a 3 bike rack, a 4th bike adapter is also available.