Depends on what vehicles they're coming from. 98% of cars do not have 650+ HP/TQ and do not accelerate form 0-60 in < 3.5 sec. BUT, again, the differences between the MS Plaid and the MS LR are enormous in terms of performance; the Plaid appears to be a whole new animal. Whether or not you think it's worth the extra $40k-$50k depends on a lot of factors and depends on what you think is "fast" and "high performance."
Having test-driven a 2020 MS Performance just one time, I quickly understood what all the fuss was about with Tesla (especially after driving a Jag I-Pace with just 400HP/512 ft/lb TQ for just over 2 years). In the 2020 MSP, I felt like I was in my GT-R but it was silent of course and 100x smoother, silky, awesome tech, and heavy feeling like a tank vs. the GT-R...but the acceleration was similar to the GT-R. I probably could've been quite happy with a new 2021 MS LR with all that power, but I know myself, and as long as I could afford the Plaid, I was going for the top-dog, the one with 1,020HP/1,050 ft/lb TQ...the one that's currently the "quickest production vehicle in the world."