Work: http://test.musicbrainz.org/work/3407f037-293c-4a9f-8c86-ed45a1fd87d1/edit (huge "Submit" button to the right)
Recording: http://test.musicbrainz.org/recording/ebf8d12a-67ce-4502-84b6-dad340592d0e/edit (same)
Release: http://test.musicbrainz.org/release/d82bf795-0b1e-4ab2-9b5b-7997cf252701/edit (green "Enter edit" button to the left)
Merge step 1: http://test.musicbrainz.org/recording/ebf8d12a-67ce-4502-84b6-dad340592d0e/merge?filter.query=%E7%B0%A1%E5%96%AE%E6%84%9B ("Merge" button to the left with completely different styling)
Merge step 2: http://test.musicbrainz.org/recording/ebf8d12a-67ce-4502-84b6-dad340592d0e/merge?dest=b4ced55b-b128-4ea9-9f9d-8de834b8342f ("Enter edit" to the left with completely differeny styling)

The huge "Submit" button seems to be the most common one. This bug report is about inconsistency, but I might add that that button is way too big in my opinion, and not where I would look for it (under the form).