That works unless you have a lift on your truck. Plus it's hard to unload them with that. I bought a ATV ramp that folds up, and it made my life a whole lot easier.
Well my father-in-law is tall so that helps.
Otherwise I just use 2 boards when I load into the truck myslef(stock gmc, no lift). One ramp for the bike and one for me to climb.
I've used a Floe tri-fold ATV ramp, even on a truck without lift, it was hella steep since it was so short.
I imagine if you found a longer ramp it would be better, then you could just hop on and coast the bike down. That would take away worrying if you have your tire lined up to the 2x6 or if it's gonna drop off halfway down.