Eva, I played DDO for about 3 years before lotro
I played on a few different servers though not on Argo. I liked DDO a lot too, for several reasons:
--Character skill customization is 100x what we can do in LotRO. You can develop many different ways to build a character within a single class, or you can multi-class with even more possibilities.
--The physical combat is more like RL fighting, with bonuses for flanking, sneak attack, positioning, and the rules around armor class and to-hit bonuses are much clearer. Spell casting is also very clear, and very much in the traditional D&D model of spell casting.
As a result you can take down some pretty big mobs with skillful combat technique or spell casting, even if they are much stronger. Or you can get very quickly get your head removed
I liked the fact that combat was sometimes more than standing in one place and clicking skill buttons, you pay attention to more tactical factors in a difficult fight.
I eventually left some very good friends in DDO though to play LotRO because of a basic difference in the games that fits my lifestyle better.
There are not very many PvE environments in DDO, at least when I played, and for most of them there are one-time achievements that you can earn there. So most of the game play is in quests. The time required in quests is often long as you level up, so entering a quest with a pug or guildmates is often a 2+ hour time commitment. And there is a culture of doing quests at or near level in DDO (because there is no xp if you don't) so at higher levels if one member of a group drops it often makes it much more difficult for the remaining team.
The dedicated time commitment is the part that is tough for me. When my job suddenly got super busy for 18 months I couldn't commit to long quests any more. Now I often play for that long in lotro, but my play is sometimes interrupted with children waking up, work, or sudden onsets of sleep
Other reasons have kept me in lotro too: the immersive Tolkien environment, the huge expanse of Middle Earth to explore at my leisure.
The thing that most keeps me here though is the other players
Being in a good kinship is key, for me, because being with other players really makes the game come alive for me, and introduces me to some very interesting elves!
Anyway, I agree that it's a fun game, and it's interesting to see the differences from lotro. I only play occasionally now with my sons, but if I do again I'll roll a character on Argonesson