TL;DR - Worth every penny, knowledgable tour guides, adventurous 4x4 offroading in Land Cruisers, see 90% of the park in 5 hours and arches you can't get to with your own car. HEADS UP: Take motion sickness pills if you are prone to getting sick (we had a few in our group who tend to sick, but they were fine on this trip fortunately)
We had our first day in Moab free and didn't know what to do with it. Saw all of the positive reviews here of the Navtec 4x4 expedition, so thought we'd give it a try.
WE'RE SO GLAD WE DID!
Chose the half-day tour starting at 1pm after calling ahead of time. They recommended the afternoon this time of year due to the amount of sun before sunset, temperature, etc. Suggest you do the same in order to go at the best time of day.
We had a group of 6. The Land Cruisers fit 4 guests + the tour guide, so groups with multiples of 4 are ideal. There wasn't anyone else booked at our time, which meant we took two vehicles in groups of 3. Essentially, we lucked out and got a private tour. :)
Tony and Tyler were our guides and they were fantastic. Very knowledgeable about the area and were able to voice over everything you'd want to know while driving around the outback. They also take into account your group's preferences to optimize your time (they said were a relatively more active group, so they adjusted the trip accordingly). We felt very safe driving around. The roads get GNARLY with steep inclines and jostling but they handled the twist, turns, and rocks like true professionals. You definitely can't do a lot of the back "roads" (I say "roads" because they are washed out riverbeds that double as your 4x4's path) on your own unless you are extremely experienced. Take motion sickness pills if anyone in your group tends to get motion sickness. You get tossed around a bit, but it's all part of this awesome experience. Don't forget to bring cash to tip, not everyone has Venmo.
They took us to Eye of the Whale and Tower Arch. We got out for a few small hikes, sauntering our way up to these magestic works of nature. We hardly saw anyone else out there -- getting off of the roads and away from the crowds makes you feel like you have the desert all to yourself. After the outback, they take you all the way through the "main" portion of the park so you can see what the crowds see. They also recommended how we should use the rest of our time in Moab, which was very helpful.
I can't recommend this trip enough if you have a moderate sense of adventure and want to efficiently see what Arches has to offer. Definitely will use Navtec again.