I got LotRO about a month ago and I like it more than WoW, not saying WoW is a bad game, I just didnt get into it (sad, too, because I still play wc3, and most of blizzards older stuff)
I cant give you reasons, both games have good things about them, I just liked LotRO more.
Actually...
WOW = PVP/COOLER ARMOR
LOTRO = SOLO/STORY
(They both have pvp and good solo but each is stronger in its respective aspect)
I recommend you try the trials, each game offers them.