The RX is Lexus\u2019 top-selling sport-utility vehicle, topping 111,000 units sold for each of the last two years. The \u201cR\u201d might just as well stand for right-sized, and that in turn may explain its popularity compared with Lexus\u2019 other four SUVs \u2014 two smaller, two bigger. What\u2019s \u201cright\u201d about the Lexus RX 450h, the model we test-drove? Well, a lot of things. The front seats are as comfortable as any we\u2019ve sat in, and the back seat is roomy enough to accommodate six-footers. The ride is impeccably smooth, and the car does a terrific job of hushing road, engine and wind noise. The interior materials and styling are of the highest quality, constantly reminding drivers and passengers that this truly is a premium luxury SUV. The V-6 engine, with an electric motor in each of the front wheels and a single motor serving the rear wheels, generates 308 horsepower and delivers good fuel economy; we did a little better than the EPA rating of 31 mpg city, 28 highway. Of course, if there was any doubt about the RX 450h\u2019s quality, the sticker price offers a reminder that you get what you pay for. The base RX 450h starts at $47,720. Priced at $45,070 in base trim, the RX 350, powered by a 295-horsepower V-6, falls far short of the 450h in fuel economy at 20 mpg city, 27 highway. Our 450h, with several options, had a sticker price of $58,490. Our Nori Green Pearl 450h was equipped with a continuously variable transmission with paddle shifters; Bi-LED headlights; the Lexus Safety System Plus 2.0; Apple CarPlay; Android Auto compatibility; 4GB WiFi; satellite radio; dual-zone climate control; power tilt and telescopic steering column; reclining and sliding split rear seat; and power liftgate. The safety feature included lane-tracing assist, road-sign assist, pre-collision system with pedestrian detection, dynamic radar cruise control, lane-departure alert with steering assist, and intelligent high-beam headlights. All of these features are standard. The all-wheel drive system bumped the base price up to $48,750. We were disappointed to note the highly desirable blind-spot monitor with intuitive parking assist, panoramic view monitor and rear cross-traffic braking was a $1,865 option, rather than standard on this luxury SUV. Also optional were the heated and ventilated front seats, panoramic moonroof, head-up display, 20-inch wheels and touch-free power rear door with kick sensor. The navigation system, Mark Levinson 15-speaker premium audio system and 12.3-inch display added $3,365. Lexus has plenty of company in the midsize luxury SUV game. Among the top choices are the BMW X5, Mercedes-Benz GLC, Porsche Cayenne, Jaguar F-Pace, Acura MDX, Infiniti QX60, Lincoln Nautilus, Cadillac XT5 and Volvo XC60. Also worth a look, once it arrives on these shores from South Korea, is the 2021 Genesis GV80. With a starting price of $48,900, it\u2019s likely to cost thousands of dollars less expensive than similarly equipped competitors. The 450h earned an overall score of 5 stars in U.S. government crash tests. Steven Macoy (firstname.lastname@example.org) is a longtime car enthusiast and full-time editor who lives in Bethel.