I'm an Rivian R1S owner and a Lucid Air owner. Here are my immediate thoughts:
1. Tesla has attracted many people who view cars as appliances with their emphasis on pushing FSD. As a a car guy, FSD is literally the last thing I want in a car. That said, I couldn't tell you how FSD compares to what Lucid offers, because I don't have Lucid's DD. Rivian's equivalent does everything I would want in such a system and nothing more, which is to make long highway journeys less taxing; I find it quite pleasant for that purpose. For what it's worth, I know that Rivian's R2 will include Rivian's improvement on its current system, and given its generally great software, I expect it to offer a great experience. RJ Scaringe, Rivian's CEO and Founder (and antithesis to Elon) has put a lot of emphasis on its next generation of driver assistance systems by including more hardware in the Gen2 R1s and I have no doubt it will be offered in the R2.
2. The Gravity and R2 are extremely different vehicles. I haven't driven the Gravity, but based off what I know about the Air, the overall design and engineering philosophy of Lucid, and the choices made by the design team, the Gravity is a full featured, highly-engineered 7 seat crossover that performs with the very best vehicles on the market, bar none. It offers the smoothest, quietest, most competent driving capabilities in a shape that will accommodate many full sized adults and their gear without the bulk and inefficiencies that typically come with such vehicles. In short, it's probably one of the most compelling vehicles to own at present if you have many people to regularly transport. As such, you'll pay for the privilege - it's priced like the luxury performance vehicle it is.
The R2, on the other hand, is Rivian's "volume" car; it's a smaller R1 with decontented features that will allow Rivian to sell to a larger population and thereby put Rivian on a path to profitability. It too, will be a major player in its class, but it's not "the whole enchilada" like the Gravity is. I have no doubt that the R2 will be a nice vehicle, but it won't be anywhere near the Gravity in terms of overall driving experience. Very, very different vehicles.
3. The R2 makes a lot of sense as a Model 3 replacement. I've sat in the R2 a few times and it's "right sized". Believe it or not, it's the same length of the Model 3 at about 185" long with a 2" longer wheelbase and thereby will have more passenger room. With its square shape and hatch, it will also have tons more cargo and headroom and increased shoulder room with its more generous tumblehome. Rivian has stated that the R2 range will be quite broad, offering everything from a single motor, stripped-out value model, to a fire breathing tri-motor variant with all the bells and whistles. I have found Rivian's driving modes that offer the gamut from efficiency (turning off the rear motors in my quad motor R1S, leaving only the front motors activated) to snow mode, and rock crawling modes to be very well calibrated; I expect R2s driving modes to offer lots of capability that will differentiate it from more pedestrian competitors.
Overall, your individual preferences will determine which route you go. If you demand the very best, the Gravity is your answer. If you're price conscious, don't want/need the extra refinement of the Lucid, and favor driver assistance above all else, the R2 will probably be the more sensible choice. Either way, both are big wins coming from a Model 3.
