For a story on NBC News, I had a chance to dig into the debate over the latest changes coming to Delta Air Lines SkyMiles frequent flier program.

Here’s a rundown of some of the changes and some expert takes on the carrier’s move:

Next June, Delta Air Lines becomes the first of the “big three” U.S. airlines to ditch the classic fixed miles-for-a-free-flight system in favor of a supply-and-demand scheme that, in many case, will likely require more mileage points to fly on more popular routes or at the last minute.

JetBlue, Southwest and Virgin America already offer this type of award program.

Delta announced the change by saying that “the number of miles needed (for a free flight) will change based on destination, demand and other considerations,” beginning on June 1, 2016.

Other changes take effect immediately.

Delta spokesman Anthony Black said “most award prices will stay the same, with a greater availability of awards at the lowest prices and some new 7,500 and 10,000 mile one-way awards. Members can take advantage of lower prices immediately, while other price changes won’t take affect for travel more than 10 months from now.”

While some changes should make it easier for passengers to access award seats, others may increase the amount of miles needed to purchase upgrades or tickets.

Many frequent fliers and point watchers have taken issue with some of the changes and the amount of information shared with customers.

“Delta will now determine demand and other factors to determine how many miles are required, in the same way that it uses those factors to determine the price of a paid ticket,” said Scott Mackenzie of Travel Codex.

Delta has removed the award chart from its site and that reduction in transparency will mean Delta customers will have a hard time determining if they’re getting a good value for their frequent flier miles, said travel industry analyst Henry Harteveldt of the Atmosphere Research Group.

Travelers may end up having to use more miles to fly popular routes at the last minute, but there may be times when the new plan works in favor of the consumer.

“If demand is soft to a particular destination,” said Harteveldt, “The cheapest tickets may be put on the market for less than the minimum 25,000 points that we have today.”

Travelers irritated by the change have vowed to stop by flying Delta.

But “the value of a frequent flyer mile is dependent on demand,” said Chris McGinnis of TravelSkills.com.

“Once demand falls off, Delta will use the SkyMiles program to woo us back with added value and perks. We just have to be patient.”