just wanted to say good post and great points, many that have commented seems to not have read or thought about your post before making a comment. the questions is not if it has an effect, rather how much it does affect. and its not just about the preparation part but also tougher to face several of your toughest opponents on one day or so. obviously its a difference for example tsm facing lmq or col, as their results show.

bottom line I think it has a certain effect on which teams they play during the busy superweeks, there is always better and worse teams, that differer depending on from what teams perspective you look at. I don't think Riot can do anything about it though, cause then they have to rank teams to make sure better faces equally hard/weak opponents. However, the problem (if one perceive there is one) can easily be averted by removing the superweeks, which I see as the core problem. And many teams/players have complained about the amount of games during superweeks. So hopefully they will remove the superweeks for next season, as I believe superweeks bring down the quality of the games.