I imagine they would be similar to a cochin/silkie cross but without the possibility of dark skin and extra toes. Probably end up with a more squat looking polish with a smaller crest and crummy leg/foot feathering. I believe polish have someone jumpy personalities, so I don't think that would be an improvement. Both of them are awesome breeds on their own and their opposite body types make them very striking. I think a cross would be sort of blah in my opinion, aside from the normal distaste of combining breeds.