SCOTTSDALE, Ariz.—JSX likes to brag that you don’t need to show up at the airport until 20 minutes before your semiprivate jet takes off.

This newbie should have listened. I arrived at noon for my 1:20 p.m. flight from tiny Scottsdale Airport to Las Vegas in early June. Employees were in the middle of a training session. There was no one in the gate area but a pilot. And there were no bars or restaurants to pass the time because the air carrier operates out of an office park. (The departure lounge serves only tea and coffee.)

There was one benefit: As soon as the meeting ended an employee came over to the couch where I was sitting to check me in.

“I know you’re just getting situated so I’ll come to you,” he said, checking my ID, swabbing my backpack for explosives and handing me my boarding pass. That’ll never happen on a major airline.

JSX’s proposition, plastered all over social media, is undeniably alluring. No traipsing through crowded major airports, no clogged TSA checkpoints, no middle seats. Instead there are free checked bags, in-flight drinks, Starlink Wi-Fi and a generous pet policy. One of its many mottos: “Flying, we fixed it.”

You pay for the perks, of course. My round-trip ticket from Scottsdale to Las Vegas, an hour-long flight, was $644 less than a week out. That’s unthinkable to travelers who regularly snag round-trip tickets on this route for as low as $150.

But it doesn’t look so bad to last-minute business travelers or spontaneous vacationers. Southwest and American each were charging $555 last minute on my travel dates—in economy.

JSX aims for the sweet spot between economy and domestic first class prices. That can still mean round-trip fares topping $1,700, especially on longer flights like Westchester County, N.Y., to Florida in peak season.

JSX wins hands down in that scenario unless you loathe small planes or need frequent flights.

The JSX departure lounge at a private terminal in Las Vegas, its busiest city. Photo: DAWN GILBERTSON/WSJ

Red-carpet treatment

The rapidly growing Dallas carrier, a public charter operator, uses 30-seat Embraer regional jets and just announced plans to add ATR turboprops later this year so it can fly to more airports. It currently serves 28 destinations in eight states and Mexico with a fleet of 48 planes with most routes less than daily. (Southwest has 800 planes).

Flying JSX was a breeze, early airport arrival and all. Boarding was civilized. You pass through a metal detector and personal items are hand inspected. X-ray machines are replacing the inspections this month at most of its airports after competitor lobbying about what they called an unfair advantage.

It’s hard not to snap selfies on the walk to the plane like you’re a Real Housewife.

Nicki and Martin Wilson surprised their 21-year-old daughter, Taryn, with a JSX flight to Las Vegas for a Kenny Chesney concert. The college senior heard about JSX from YouTube videos. (It must be a Gen Z thing. My son said it was “sick” that I got to fly JSX.)

“For two years I’ve been like, ‘I want to fly this airline,’” Taryn Wilson said.

The Wilsons’ one-way tickets, purchased in January, were $264 a person. She and her sister Tristyn, a 26-year-old teacher in Nashville, Tenn., documented every step of the trip on their phones.

Also on board my flights: a Los Angeles-based music producer who says he’s taken more than 100 JSX flights. (The flight attendant recognized him from a flight the day before.) A woman with a Maltese-Yorkie mix in her lap who said she flies JSX every week, and a mortgage executive who said he was only on board because his plane was in the shop.

On board

I was surprised to find those annoying seat-assignment fees on JSX. I dodged them by not picking a seat in advance for either flight. There was no risk because every seat is a window and aisle seat in the plane’s 1×1 configuration. I was assigned 14A on the way out and 12A on the way home.

The legroom is dreamy. There are no overhead bins to bonk your head on. Bags either go under the seat or under the jet. The latter are waiting outside for you after deplaning. No baggage claim here.

JSX’s planes are about 20 years old so the interiors aren’t flashy. It all felt premium, if not plush.

The trendy snacks reminded me of Delta ’s Comfort Plus snack basket and JetBlue’s lineup. (JetBlue is an investor in JSX, along with United .)

Robin Leach wouldn’t be the target customer if he was still around, says JSX Chief Executive Alex Wilcox , a former JetBlue executive.

“It’s not champagne and caviar and lobster thermidor,” he says. “It’s what people really want.”

He calls JSX a time machine for busy travelers.

I finally got the hang of it on my flight home from Las Vegas, the carrier’s busiest station. I checked in at JSX’s hangar at 1:20 p.m. for my 2 p.m. flight.

Minutes before landing, the valet service JSX uses in Scottsdale ($40 a day) texted a link to pay the bill while taxiing so my car would be waiting.

Cue “Glamorous” by Fergie and Ludacris.