A longer ramp takes out some of the "going over backwards and breaking your neck" excitement. We have had a number of folks hurt themselves big time on short ramps, particularly if hitting the brakes (and flipping over backwards) when coming down the ramp too quickly, or not crouching forward over the ATV or mower (the higher your center the gravity, the more likely you are to flip). I've the longer ramp from Northern Tool, the 3 segment fold-out, and it's fine. However, I've gone one further on safety. I've U-clamped a chain between the 2 tiedowns on the insides of the front of my pickup bed (like all pickups), and attach the winch of my ATV to such. I can winch my ATV on and off the pickup, with me sitting on the seat of such, with no rollover risk. Heck, I could probably have gotten away with a shorter/steeper ramp.
And, I have a 2006 Tundra - tailgate support not an issue as yet (500 lb ATV, 180 lb rider - dozens of times, and no signs of support cable or fastener wear).