There is an active thread on the same subject called, "New Truck! 2500 vs. 3500".
The cab lights are no longer standard with a 3500 SRW, they are with a DRW however.
Another difference between the two is the tag on the door jamb with the higher load capacity on a 3500, which could be very important in case you are involved in a unforseen mishap with a heavy load, such as a cab-over-camper. State troopers and insurance company's look at such information to determine fault. Add on air bags are not taken in account.