I booked basic economy flights with Delta and United. They felt like 2 completely different classes.

I flew from NYC's LaGuardia Airport to Denver International Airport with United Airlines. My $165 basic economy ticket didn't include carry-on luggage or a seat selection. I paid an additional $40 to check my bag, so, in total, I paid $205 for this flight.

I arrived at the airport about an hour before 10 a.m. takeoff and got my seat assignment when I checked in.

The flight had 166 seats and in-seat power for rows one through 21, but I couldn't access an outlet since I was seated closer toward the back.

While my flight back was on Delta's Airbus A321neo, the airline says its Boeing 737-800 fleet has 160 seats, all with power outlets.

My seat was between 16 and 17 inches wide with a 30-inch seat pitch. With passengers on either side of me, I felt cramped in the small space, and even at 5-foot-3, there wasn't enough leg room for comfort.

The seats on Delta's Boeing 737-800 are slightly larger, with an inch wider seat pitch.

United Airlines told Business Insider that a new aircraft with upgraded interiors and more overhead bin space was coming soon as part of the United Next initiative.

There was a seat-back entertainment screen in front of me with access to DirecTV. I could have used my phone to access a library of shows and movies with the United app, but I didn't want to watch on a small screen.

I sampled the cable offerings, but there wasn't much to watch. The remote on my armrest was sticky, and I found it tough to push the buttons — especially when the passenger next to me was resting their arm on it.

United told BI that the upgraded United Next interiors would have touchscreen entertainment systems, Bluetooth connectivity, and power outlets at every seat.

Delta began refreshing its Boeing 737-800 fleet in January with more seatback entertainment options, and some are already in service.

It had a modern faucet, too.

I booked my basic economy flight from Salt Lake City to NYC with Delta. The $175 ticket included one carry-on bag but no seat assignment.

I arrived at Salt Lake City International Airport about an hour before my original 5:35 p.m. flight to Newark Liberty International Airport in New Jersey. When I checked in, I learned I'd get my seat assignment at the gate.

Once past security, I stood in line at the gate for my seat assignment. I overheard the attendant on the phone saying the flight was overbooked and another flight to John F. Kennedy International Airport was leaving 10 minutes later with plenty of empty seats.

JFK is much closer to my NYC apartment than Newark, so I told the attendant I'd be happy to switch flights. She thanked me and gave me a new boarding pass for the 5:45 p.m. flight.

The plane, which could seat 194 passengers, had many empty seats, and I was lucky enough to land a row to myself.

The seats were 1 inch wider and felt cushier than the ones on United. I was also surprised that a 1-inch wider seat pitch made a huge difference in legroom.

United's Airbus A321neo has a couple more rows of seats than Delta's, and the seats are a bit smaller and have one less inch of legroom.

The entertainment screen in front of me showed hundreds of movies and TV shows, from Blockbuster hits to independent films. I also had access to a power outlet to charge my phone.

The fixtures looked slightly less modern than those on the United flight.

From the included carry-on bag to the more comfortable seats with additional entertainment and amenities, Delta's basic economy felt much more comfortable for $30 less.