I adore Eloisa! For the longest time, I liked Louisa and I disliked Eloise and Louise. Then, one day, I stumbled upon Eloisa, fell in love, and now I love Eloisa, Eloise, and Louise, but Louisa bores me and feels weak by comparison. It's one of the few times where my opinion has really turned completely around.
Anyway...I think most people will get Eloisa, particularly if they're at all familiar with Eloise or Heloise. Eloisa Danielle is pretty, although I'm not crazy about Danielle. Like Nicole and Michelle, Danielle feels worn out and desperately in need of a long rest. I think it's okay as a middle name, though.