[JTD]

Two quick things to point out:

1. Someone mentioned bed size being the same. This is not necessarily true if you are using a P4X CC as your baseline, which has a 58.5" long bed as it's only option. Nissan did this to keep the wheelbase short and bed overhang to a minimum for offroading.

2. My truck hauled 4 adult men and all our gear on a ski trip a couple weekends ago. Four hours to the mountain, 7 hours of riding, and 4 hours back in the same day. The two in the back were between 5'10" and 6'1". Front passengers were about 5'10", and had the seats moved to a comfortable but not cramped position. The back passengers didn't complain.

I might be more inclined to get the modern design of the Colorado (which means more modern/hopefully better engineering analysis methods in addition to all the creature comforts), but the Nissan is a proven design with most or all the kinks either worked out or well documented. If you want to go with Nissan and don't plan to go offroading much, I'd suggest looking at the SV CC with a 6' bed.