When we first stopped and trekked up to the lookout, the view was absolutely breathtaking. In fact, it looked fake! Like the backdrop of a movie soundstage. This is definitely a must see if you're in the area. We didn't have much time that day to explore, since it was a 90 minute drive one-way from where we were staying in Sunriver, so it would be fun to return some day to spend more time in the park itself.
We stopped at several lookouts along the way, but barely scratched the surface of the 33 mile drive around the rim of the crater. Not to mention the many hikes that can be taken, including at least one that goes down to the lake itself.