I think trucks that have four full size doors look more like crucks, than trucks. The extended cab in my opinion has a more sporty look to it, and looks, well more like a truck.

 

I have a crew with the short bed. My family of 6 (wife, 11,9,8, and 2 year old) fit comfortably on 3-4 hour trips. The bed is near useless. I put a bed cover on, but wish I would have spent the money on a topper. I use mine for farm type work, so I need a good bed.

Wish I had the medium size bed. It would have been perfect.

 

I have the 06 Crew Cab and I love it. There is more leg room in the back than the EXT cab, and the bed on a 1500 Crew is 5.8 feet, which is close to 5 feet and 8 inches. You can get a Crew 1500 HD which will give you a 6 foot bed, but the truck is longer. Another point is that the EXT w/6 foot bed is the same length as the CREW w/5.8 foot bed. Check the dimensions on a website like autos.yahoo.com.
The bed is shorter in the Crew, but it all depends on what you haul. I have a bench seat in the front and I have carried six people around in it for distances under an hour, five adults and one child in a wide bulky carseat. Everyone was comfortable. I love this truck.