If noise will ever be an issue, it will be while towing heavy! The larger exhaust helps if you are going to modify for power in the future. On a stock truck the stock exhaust size is fine if you can just get rid of the back pressure of the stock muffler. You WILL notice a reduction in turbo lag when you reduce the back pressure! It helps total horsepower, but not much. The big difference is at part throttle! You might notice an improvement in fuel economy... it made quite a difference in mine!
Drone is a danger without a muffler... a resonate sound in the cab that vibrates everything including your head. The quieter the exhaust, the less chance of drone. If you like noise, drop the muffler. If you like a quiet cab while towing, either gut your existing muffler or buy a long, large diameter, straight through muffler from a big truck.
Are you able to do your own work or will you take it to a shop? I really like my gutted muffler. It is virtually the same noise level as stock, but sure runs a lot better! It took only a couple of hours of work and a few welding supplies... virtually free if you can do your own work! I can tell you how to do it if you are interested.
Steve
Steve