I flew long-haul on United's aging Boeing 777 in basic economy. A few key updates made it feel much more modern.

• I flew on a decades-old United Airlines jet from New Jersey to London in July.
• With modern cabins and Bluetooth, the dated Boeing 777-200 didn't look its age.
• I was particularly impressed by the food, which had been lackluster on my previous United flights.

I've flown United Airlines across the Atlantic at least a dozen times for my job, and it's always been hit-or-miss.

Much of that comes down to the aircraft type: Some of United's older planes, like its Boeing long-haul 767s and 777s, still have dated cabins and older technology.

But amid booming premium demand, United is working to modernize its fleet and cabin experience from nose to tail, including its aging Boeing 777-200s, which have an average age of about 27 years.

I flew on one of the renovated 777 planes from Newark, New Jersey, to London in July to experience the upgrades. My specific plane was first delivered in 1997, but the modern seats and large seatback screens with Bluetooth connectivity made that hard to tell.

I was also impressed by the meals. United's food has often left much to be desired on my previous long-haul flights, but the chicken dish and breakfast pastry I had on this trip were surprisingly flavorful.

Here's what the full seven-hour basic economy flight was like. Business Insider paid $900 for the round-trip ticket.

Unlike its domestic basic economy fares, which include only a personal item, United's long-haul discount fares also permit a free carry-on.

The ticket allowed me to select a seat at check-in, and the only remaining aisle seat — my preferred seat — was in the center section of the very last row. It was near the galley but ended up being a great place to escape the crowded coach cabin.

I have the United Explorer credit card, meaning I get a free checked bag, two free United Club lounge passes a year, and Group 2 boarding.

I used all of the perks during this flight. I lightened my haul by checking my duffle, and I was among the first to board the jet. And the United Club was huge; I enjoyed a light dinner and drinks before my red-eye flight.

United's renovated 777 has comfortable economy seats, complete with a headrest, a large seatback screen, power ports, and Bluetooth.

However, these planes have a 3x4x3 seat layout. That means it's a 10-abreast cabin with 17-inch-wide seats, which are an inch narrower than the setup before United changed it in the mid 2010s.

Having flown on 777s with both layouts in the past and being average-sized, I couldn't tell the difference.

But I can imagine the middle seats in the middle section may feel cramped, so it may be worth paying extra for an aisle or window seat.

I didn't pre-select a seat like I usually do to secure an aisle, planning to pay if I couldn't snag one for free at check-in. Luckily, there was one left in the very last row of the cabin: seat 53D.

While many people avoid proximity to the galleries and lavatories, I don't mind the easy access to the bathrooms and the extra privacy, since I'm out of immediate view of everyone else.

I was impressed with the Bluetooth connectivity. United has been rolling out the feature on its planes for years and plans to equip over 800 planes with the perk by 2032. But the rollout has been slower for its widebodies, so it was a nice surprise to find it on the old 777 I flew.

The setup was easy: I put the headphones into pairing mode and disconnected them from other devices. I prefer using my own headset over United's cheap wired ones, which I find make the audio scratchy and too quiet.

I've not always found United's long-haul food to be the best, but it has actively been addressing the problem. It recently partnered with professional chefs to curate a new menu for its Polaris business-class passengers, and I can tell it has beefed up its economy offerings, too.

My economy meal service was much better than I remembered from previous flights. We got cheese and crackers shortly after takeoff, and then dinner a little later.

I had the chicken dish with a side salad, bread, and a brownie. There was also a beef and a vegetarian option; my friend had the beef and liked it.

Breakfast was a turkey ham and cheese sandwich. Everything tasted great, and I liked the pacing of the meals.

A blanket and pillow are standard on long-haul flights, especially red-eyes. The blanket was soft and warm, and the pillow had a cutout so I could wear it around my neck.

Pairing that with the headrest made sleep somewhat easier, though I struggle to sleep on planes anyway. I slept about four hours total.

I've always considered United a good airline, despite its sometimes lackluster food, but its modern cabin and improved meals made a noticeable difference on my economy flight to London.

And although not on my plane just yet, I'm excited to see United's new "Relax Row" — essentially a bed in economy — will be added to its Boeing 777 and 787 widebodies starting next year.

United has also added a snack bar and extra elbow-room seats in economy on its brand-new Airbus A321XLR jets.

It's refreshing to see an airline investing in the economy cabin, where a majority of its customers sit, rather than just its VIP sections.