I have now spent 100+ hours with Pantheon: Rise of the Fallen early access and can confirm from my initial impression that Visionary Realms has succeeded in recreating the feel of classic MMOs like the original EverQuest at release in a base form.
Interacting with the community has been enjoyable most of the time, while the basic gameplay loop feels great as someone looking to have a classic MMORPG experience, and the slow character advancement feels rewarding.
Make sure to check out my Pantheon: Rise of the Fallen Review-in-Progress for more details in these areas. But even with all the current content offered by this Alpha build of the game, the more I play, the more I acutely notice what's missing and how it would drastically improve the experience if implemented well.
Beyond the core systems, such as Skill Mastery and Perceptions, many other elements would go a long way in creating more fun and unique experiences for players.
For example, let's start with something simple, like the three missing races. The Archai, Gnomes, and Skar have interesting backgrounds and unique elements in the setting of Terminus.