Ibn Ezra: They are great. This is a doubled root (Reish Beis is repeated), like Galgal. Malbim ? Gadol refers to His Hashgachah within nature, like I explained "ha'Kel ha'Gadol." He is the first and last cause of everything.

Malbim: Wonders in which He changes nature are strong; they pertain to Gevurah - ha'Kel ha'Gibor.

Malbim: The former refers to Kemah Ravrevin, and the latter to "v'Simhohi Kemah Sakifin". I explained in Tehilim ("Malchusecha Malchus Kol Olamim u'Memshaltecha b'Chol Dor va'Dor") that Malchus is ruling via nature. Memshalah shows that He changes nature and rules by force as He desires; it is against the subjects' will. Meluchah is with their consent. L'Olam is the eternal time, which is not divided; it corresponds to conduct fixed from Bereishis. Dor va'Dor is eternal time divided into generations. It applies to wonders done at particular times, based on a need at the time.