Charm Overhaul: The revamp and extension of the old charm system also affects free account players
Stash Expansion: They can also store items in unused condition in their stash, just like premium players
Cyclopedia: They can use the Magic Archive to view information about spells and runes. They can also benefit from the improvements made to Combat Stats.
Exaltation Forge: They can use it to tier up their boots.
Quest Log/Quest Tracker: They can also take advantage of all the improvements.
I haven't played as a free account in decades, so I can't say whether these changes will have a big impact on their lives. But I do believe they are positive changes, especially the stash expansion.