I find LoTRO very fun and enjoyable.
It is quite a change of pace from DDO, much more kicked back and casual.
I don't really agree on it being grindy, way less grindy than DDO that is for sure, and if you are doing at level quests you can go from 1-140 pretty fast, take part in the festivals and learn the quick quests, those are easy XP. You can also use XP accelerators which help a lot.
I find LoTRO is great when you really want to submerge yourself in a great lore filled adventure, gameplay is a little different than DDO, I mean don't go into it thinking it is the same as DDO but with the LoTRO storyline, because it isn't, not even really close.
They are two very different games for sure.