5 on 4 off sounds good untill you remember a D/O can end at midnight and statr at 6 am with easy and often does with those 4/5 sector days. You'll have more evenings at home when you can have a few beers with Monarch if you draw out a typical pattern and do the sums.
Also hours spent on D/Os is very similar, and in fact quite a bit better in Monarch if you allow that after a Mon D/O you generally can't fly the morning wave or fly the afternoon wave before one.
Has even a single pilot left Monarch for easy yet (other than CTC)?