I like both, but I prefer
Eleanor. It sounds so dignified and beautiful.
I pronounce
Elena e-LE-na and
Eleanor EL-ə-nor.
I don't really care for
Ella because it sounds childish to me and is overly popular these days, but it's better as a nickname than a full name. I don't mind it all that much as a nickname for
Eleanor or
Elena. I like
Elle and
Ellie much better, though.
I really like
Elena Fleur and
Eleanor Simone.