Most often I am getting disconnected and the opponent gets time advantage despite I have 150 MBPs connection. This is just because I didn't subscribe for any of their paid service. I guess others also might face similar situation
Other than ads, not being premium does not impact your connection.
For things you can do to minimize connection issues, check out the following.
https://support.chess.com/en/articles/8652402-how-can-i-optimize-my-online-chess-performance
https://support.chess.com/en/articles/8584209-how-do-i-fix-my-disconnect-lag-issues
Most often I am getting disconnected and the opponent gets time advantage despite I have 150 MBPs connection. This is just because I didn't subscribe for any of their paid service. I guess others also might face similar situation