I did a ton of research online and with TripAdvisor before my kids (older kids in their 20's-30's) and I decided on which tour and which company we were going to go with. We wanted to go off-road but I also knew from experience that the guide is really the key to this because the scenery speaks for itself - and it was incredible! We chose a sunset tour would give us some amazing photography opportunities - and it did. The gal we got was new. She was nice, but she didn't have a lot of personality. She tried, but I kind of felt like we were just on a jeep ride with some factoids thrown in. It wasn't the "fun" experience I had hoped for, but it was beautiful and it was enjoyable. I just feel like it could have been a lot better. She did take us down an alternative, and very bumpy path to try to get a glimpse of some wildlife which was cool, but no luck.
Side note, it was a little confusing to find so just be sure you know which place you are going to. I didn't pay close attention to my booking details I guess and we ended up at a difference place and they routed us to the correct location. So just pay attention to where you are going since there are so many there.