Online or Not online???

I have had seats reserved in PE for flights in August to MCO from MAN in the bubble / upstairs
Have heard a few people have had problems with online check-in particularly with children and have not been able to get the seats they wanted and have been dumped downstairs. We are 2 adults and 2 kids. Has anybody else succesfully reserved seats and then checked in a family of 4 with and aisle between the two seats. Fr example us all sitting in row 79.
What would you do then guys??? Do online and hope it works or get to the airport early to ensure our best choice of seat and to hopefully make sure we get upstairs
Have heard a few people have had problems with online check-in particularly with children and have not been able to get the seats they wanted and have been dumped downstairs. We are 2 adults and 2 kids. Has anybody else succesfully reserved seats and then checked in a family of 4 with and aisle between the two seats. Fr example us all sitting in row 79.
What would you do then guys??? Do online and hope it works or get to the airport early to ensure our best choice of seat and to hopefully make sure we get upstairs