That's it mostly, although the amount saved is very small. There are two benefits from removing weight on the hubs/brakes/wheels. One is unsprung rotating weight. It's the most beneficial to remove because it makes it easier for the wheels to start rotating. I've seen different opinions as to how much benefit; some say it's like removing 4 times the static weight from the car, and some say it's like removing 10 times the weight. Whatever the ratio is, if you remove at least 5 lbs per wheel, you can feel it.
The other benefit is you're also removing static weight from the wheels. This helps improve the response time of the springs and shocks (dampers) in controlling vertical movement of the wheel.
Just replacing the stock lug bolts by themselves with titanium isn't enough of a weight difference that you would even notice it on a street build. If you're doing it for performance reasons, the cost doesn't really justify the return on the investment. They're not cheap. I've seen sets going for anywhere from $200 to $1,000 with all kinds of claimed benefits. On a dedicated race car, sure, but not on a street car.
I'm going to get a set of torx head titanium lug bolts mostly because I can afford it, and I like the way they look. Whatever difference the few ounces of weight saved makes, that's just a bonus.
Here's the style I'm looking at:
View attachment 36519