IMHO, the divide (at least in the US) is not between big and small but between public and private. In a private corp you get a chance to find an awesome work environment no matter the size and in a public, it appears, even if it had not been bad before, it's going to become worse.

PS. I am not saying that all private companies are awesome. Some are exceptionally bad e.g. Lucas Arts used to be pretty horrible. I am not saying that all public companies are horrible either - Apple seems to be all right.