I was 756 EWR back in 2015 when things were a little slower but I would assume it was equivalent to what 777 787 now. There are pluses to it such as most flights left at night so commuting to an actual flying assignment was easier. Problem I ran into was just the lack up trips available to pick up, that along with being junior, meant A LOT more nights at the crash pad/ hotel than my 737 a320 friends. The crash pad was filled with 756 guys, while the 737 guys were out flying in hotel rooms bought by the company. Also yes your days can get moved around a high can be rough on the family life. Also, the 6 days that are immovable by the company must be 6 days in a row. So while you do get one nice stretch of days off, the rest of the time expect something like 5 on 2 off.