Looking at some of the baseline CSS changes in the new version - link colors and hover states are acting differently, as are ````p```` tags.

New base styles

// excerpts from _ey-scaffolding.scss

a {
  color: $blue;
  text-decoration: none;

  &:hover,
  &:focus {
    color: darken($blue, 10);
    text-decoration: underline;
  }
}

p {
    color: $darkGray2;
}

Old base styles

// exceprts from _ey-bootstrap.scss

p {
	margin: 0;
	@include textLayout(); //uses default 15px/1.5

	+p {
		//padding-top: 0;
	}

  a {
    border-bottom: 1px dotted $blue;

    &:hover {
      border-color: transparent;
    }
  }
}