I have to disagree with Formendacil. I do think that Galdriel was inherently more powerful than Elrond but I think the comparison is to an extent pointless because the nature of their power is so different. While Elrond is descended from Luthien, (and I am not sure that the Maia thing is so significant because Melian had to "become" an elf ot bear a child..but this has been argued elsewhere...) he is also descended from men. Also Galadriel had been born in the blessed realm and seen the light of the two trees. I adore Elrond, he is one of my favourite characters. He is certainly the most learned, and the most noble and humanitarian. Since elves have little need for healing, I regard the fact that Elrond specialised in this a manifestation of his great concern for the mortals of Middle Earth. He always does the right thing regardless of personal cost. His many sufferings have not made him bitter. He is a warrior who takes no delight in killing. He is altogether most admirable. However if push came to shove, I would take Galadriel as my champion... because as well as being older & valinor born she has got a far more cunning mind.... and sneaky is useful
.
That said I think the distinctions are fine. It is certainly clear that it not all Maiar were more powerful than all Eldar. Some Elves are clearly more than matches for some Maiar... think of all those Eldar slaying balrogs. While you might argue that Saruman and Gandalf might have the edge on Elrond and Galadriel ... I doubt anyone would place Radagast ahead of them......
And ... can you really imagine Galadriel being imprisoned by anyone for a second?
I guess I find the tale of Luthien annoying because so much of her power is associated with her beauty and she uses her power for selfish means - in order to marry Beren, who to borrow a phrase is "so wet you could shoot snipe of him". And this causes death of Finrod. Needless to say I also find Arwen annoying....