I will be towing my 28' travel trailer pretty regularly. I ordered a 5.0L back in October since the EB was listed as "Late Availability" and I needed my truck ASAP...six months later and after lots of EBs shipped, I picked up my 5.0L.
With the 6000lb trailer on, you can definitely feel it, but it pulls easily.
It was a long wait, but so far, worth it.