So what's it like?
In each realm a small but varied selection of classes are available to play completely free. However, if you had a lapsed account, you can now also log into any character that has at least 24 hours played. For example, I can log into almost all of my old level 50 characters regardless of whether they are from restricted classes or not.
Returning players will find the game much changed from what they remember. With the launch of EC all alternative currencies such as aurulite and dragon scales were replaced with bounty points. For example, the quest chains in Atlantis that used to yield glass now yield bounty points, and artifacts are now purchased with bounty points instead of glass. You can get bounty points doing just about anything you like, from RvR seige battles to solo PvE, and almost any equipment in the game can now be bought with bounty points. In my opinion this is a vast improvement, the number of different systems and gear currencies that DAoC had built up over the years was bewildering. Related to this, the free "starter epics" you get from the King at level 50 have been greatly improved. It terms of raw stats they are now very solid, and will put you within striking distance of the effective caps on all the stats your class cares about. In combination, these changes mean that gearing up a new character is a lot easier now.
On the not so great side an entire expansion that many players remember fondly, Catacombs, has effectively been removed from the game (apart from the races and classes that came with it). Plans to revamp the Catacombs for the modern game once the Dragon's Curse campaign came to an end never materialized, and I'm skeptical they are even still in the works. It's been two years since the changes to Catacombs went in, and returning vets still get confused by it (Surfer18's reaction to it here is pretty typical). On Gaheris (the PvE server) this has contributed to a content gap in the level 36 to level 40 range, when the new player quest series runs out. Until EC you had two options to get through this, Task Dungeons and repeating a series of quests in Atlantis. With the launch of EC Task Dungeons have been disabled. It made good sense the close them on Ywain, it helps funnel players towards the PvP battlegrounds. However, on Gaheris most of the battlegrounds (including Molvik) are also closed. The low level quests in Atlantis also appear to be bugged, currently they are repeatable on Ywain but not on Gaheris. Taken together, on Gaheris for roughly four solid levels there is now almost nothing to do but grind random mobs to advance. Very old school . . .
How successful is Endless Conquest?
Perhaps the most important question is how successful EC has been at boosting the population of DAoC. To get a sense for this I used data reported at this excellent website, which is organizes stats published on the Camelot Herald. Pretty much however you parse things (e.g., player numbers per week below), there was a significant jump in player activity around the launch of EC. However, within a very short time nearly half of these players appear to have left. As of the week of December 15, the number of active players seems to have settled at about 50% more than the game saw in the six months before EC. Certainly a success, but probably not what Broadsword was hoping for. The game is also still at a net deficit of players (or at least player activity) compared to December a year ago.
Update Dec. 23: After fiddling with this post all weekend (e.g., expanding on why I keep ranting about Catacombs), I think I'm finally happy with it now. I also did some digging to try and figure out what caused the "DAoC crash of 2019." Between roughly January 20 and February 24 the game appears to have lost up to half half its player base. There is nothing in the patch notes from around that time that hints at a cataclysmic change to the game itself. However I did find that the free-shard of DAoC* that is currently the most successful went live on January 12, 2019. Very soon after that the live game started bleeding players (or at least the number of players logging decreased drastically), and a patch note from around this time seems bit panicked if you read it knowing everything that was going on. I tend to think that player run shards of games are generally fairly harmless, but this may be an instance where one did serious harm to a live game that was already struggling.
*For the time being I will not be linking directly to any unauthorized servers for DAoC or any other live MMOs here, though I consider cases where you literally can't play a game any other way fair game (e.g., I might blog about the current state of SWG or WAR some time).