Are you comparing the current Model X to your R1S or the older one. Also, do you have a service center near you? That is my biggest concern, along with road tripping without the supercharging network.
I really like the R1S but the above 2 concerns, along with the price tag, are keeping me from ordering one.
So many are concerned with losing Tesla's supercharging network if they give up their Tesla. And it's a given, Tesla's supercharging network is second to none. For a road trip, they're reliable in most cases and easy to use.
I guess the more relevant question is, how often do you really use it? If it's just once, twice or three times a year, is it really worth sacrificing all the other capabilities just to have a more reliable charging network a couple times a year?
For those that road trip on a very regular basis, the argument for a Tesla gets stronger. But, that also depends on where you're at and where you're going. For me, I'm in an area where EV's are common and public charging is plentiful. So in most cases, I plan my trips a little conservatively. I'll choose a charger well within my vehicle's range. Then, if that one happens to be non-functional, I know I can make it to the next one. For me, I only use public charging 2-3 times a year and mostly for just one stop. Anything longer than that, I'll generally fly to, rather than drive.
So in my case, the public charging network carried very little weight in my decision making process. I've now had the Rivian for 6+ months. I've taken a few road trips with it. A couple of minor issues here and there with public charging networks, but, have always found a way to charge without too much inconvenience. In those cases, it would have been nice to have the supercharging network. But, that was what, 2-3 days of use out of 365 days a year. They were MINOR inconveniences on a couple of occasions for 362 days of bliss. Thus, the positives far outweigh the negatives.
Furthermore, in my case, I can travel further in my Rivian than I ever could in the Tesla. A trip to Vegas, I can make without stopping. Never could in the Tesla, not even close. Also, despite what rated charging speeds are, on my same trip to Arizona, I spent 20 minutes less charging on average with the Rivian than I did with the Tesla. So, the couple of issues I had with a charger being out of service, have been further offset by the fact that, for me and repeated trips I personally take, I spend notably less time charging. Overall, For a trip of up to 500 miles, which is about the max I'm willing to do in ANY EV, I actually much prefer road-tripping the Rivian than the Tesla.
Auto-Pilot, Tesla wins hands down in highway use. However, I much prefer the system in the Cadillac, which is truly hands-free. I hardly ever used the Tesla AP because of the constant nagging. Even with my hands on the wheel, it would still tell me to put weight on the wheel or wiggle or whatever. More work than just driving myself. While Tesla's AP capabilities are superior to all others, the fact that they've chosen to keep this antiquated method of policing driver attentiveness is a big turn off for me.
In the past, my two must haves were, AP and Supercharging. Over time, after 9 years with various Tesla's, that changed. AP when it first came out was amazing. But, then all the YouTube idiots posted their stupidity and they've ruined the experience for me with all the nagging.
While not as good as Tesla's supercharging network, the public chargers are being built out for other EV's at a pretty rapid pace. In my areas, there are more than enough options. Others will need to check their own areas and map out their typical road trips to see how well the public chargers will serve their use cases. If you have enough pubic chargers along your common routes, including backup locations, then I personally prefer roadtripping in a Rivian. Furthermore, Rivian's range estimate is actually accurate and USEFUL. Tesla always says I have 365 miles in range, yet I'm lucky to get 250 at highway speeds. Completely useless range estimate. For whatever reason, they've chosen to not have range estimates vary based on each driver's real world use, as pretty much every other EV maker does.
As far as Service Centers. Out of your control. Rivian, like Tesla, offers mobile service for many things. Many people waiting for Rivian delivery are doing so because Rivian won't sell vehicles in areas they can't service yet. Many first day reservation holders are still waiting because there's no service center near the owner's location. Tesla has had 10+ years to build up. Rivian will get there. But, something to check. If there's a Rivian service center within 50 miles of your location, then you're all set and this isn't an issue. Tesla wins this category only because they've had more time to build up. But, if Rivian has a service center near you, then in those particular areas, Tesla has no benefit over the Rivian. Check the Rivian maps for Service Center locations and the Coming Soon locations. Tesla only wins this category if Rivian does not have a Service Center or one planned in a particular area where a buyer is located.