Yesterday while in Florida I played a golf course that was overseeded with Ryegrass. Most of our courses in the New Orleans area don't worry about doing this. It is mostly about keeping the golf course green than the playability of the golf course.
If you find yourself on a golf course that has been overseeded you find there are some minor things to be aware of. The first is that the ball does not roll out in the fairways as much. ryegrass is "stickier" in a way and is usually kept slightly longer than the normal bermudagrass we are used to. This is something to especially keep in mind around the greens. It will be harder to run a golf ball up to a green and you may find you have to fly the ball further.
Another thing is the rough will be harder to play out of. Because the grass plays differently you may find that your club feels like it gets stuck in the grass at impact. This slows the clubhead down and may cause your ball to come up well short of your intended target. If the grass is thin and not grown in yet you can catch a lot of flier lies that will shoot the ball longer but this is only when the overseed is new.
Just be aware of the lie you have and how thick the grass may be. If you find yourself in the rough about 5ft off the green remember to give it a bit more than you would out of bermudagrass. You may find that playing more lofted shots with the face open a small bit will work best. This allows the sole of the club to cut through the grass better. However, you should only try those shots if you are comfortable. The last thing you want to do is slide the club under the ball and only it a foot or two.
Other than those minor things the golf course will play very similar. Overseeded golf courses are beautiful as they are a deeper green than we normally see with regular bermudagrass. This is especially true when a course will only overseed the rough, or when they only overseed the tees and fairways.