I wouldn’t refer to them as pros or cons but there are definite differences, which you should understand before you buy a bronze-cased watch.
Bronze is slightly softer than steel, so marks are more likely, but… the darkening of the patina will cover for minor scratches.
Patina will develop - it will be gradual and it will be uneven.
You have to accept a change in appearance over time, even in as little as 4 weeks, but… if you don’t like it, your can reset it easily - literally 30 seconds for a rough reset, longer for full clean.
Don’t expect to get it back to new. Even with a full clean, it will look different to the brand new item.
You can force the patina if you like, to get faster and more deliberate changes in appearance. Google will give you some idea if what’s achievable and how to go about it.
In short - if you know what you’re getting yourself into, bronze can be a lot of fun.