Pros and cons of wider tires

I am getting really mixed messages about the pros and cons of going with wider tires assuming NO CHANGE in rim size or overall diameter.

In terms of ride comfort, some posts have said that wider is better because it smooths out the bumps whereas others have said there will be a decrease in ride comfort due to the wider tire contacting and transmitting more road bumps. Which is correct?

Also, is it fairly reasonable to assume that wider means decreased mileage due to higher rolling resistance?

Pros:Much better traction, more stable, generally better tire wear because you'll build up less temperature, looks better, much better in the rain, better braking action
Cons:Slightly worse mileage (probably so little you won't notice), potentially worse on the snow depending on tread pattern, potentially louder, particularly wide tires can sometimes "follow" ruts and creases on the highway

In general, the good outweighs the bad in my opinion.

First, differences in tires will have many times the impact that the difference in size you've proposed. Put another way: Making the change you've proposed may result in any particular property being better or worse and it would all depend on the exact tire you selected.

But directionally, you're looking at better dry traction, better wet traction (except for hydroplaning), worse hydroplaning, worse snow traction, worse fuel economy. Everything else is pretty much a wash!

Ride in particular would be unaffected because the section height would remain the same, even though the aspect ratio would go down.