I constructed this one at the end of the fantastic Voxas Vacation daily contest over on Logic Masters India. I wanted to explore some unusual logic using only grey dots and I really like how the break-in turned out.
Rules: Divide the grid into 1x2 and 1x3 regions. Borders must separate two different regions. Borders with white dots separate regions with the same size and orientation. Borders with black dots separate regions with neither the same size nor the same orientation. Borders with grey dots separate regions with either the same size or the same orientation, but not both.