Tennis is really fun to play. I suck at golf though lol
Golf is pretty easy once you take several factors into consideration.
1) What you see is what you're going to get for the most part. Meaning if you hold R2 to preview where your shot is going to go, it's going to go there if you hit the drive at full power or close to it. Wind plays a role but not nearly as much as most normal golf games.
2) When the ball is in the air you can mash the spin button (I think it's point the stick in the direction you want + X on PS3) and when the ball lands it'll usually bounce in the direction you pointed it. This is pretty overpowered compared to most golf games which only let you use spin during the swing, which I always felt was tough to do both at once. It really works if you think you're going to overshoot the pin, you can make it stop and sometimes even roll back.
3) Putting is a joke compared to normal golf. There's hardly any uneven ground on any of the 9 greens so if you line the marker up with the hole and hit the yellow mark on your swing you'll likely always make it.
All that being said I enjoyed my first and only round so far. It was pretty cool getting in the golf cart and driving out to the ball after every shot while watching the city go about its business outside of the fence. Really..."immersive" as people here would say. I think golf will be a lot more fun when you're able to play real people when Online launches.