For me after being spoiled by 980TI(can support 3 montiors and does not drop fps in unreal), support for 3 monitors and 2 HDD bays is a must.
It is not that hard to find new with standard hdd bay and extra one for SSD card.
But finding that can have 3 montiors connector or even 2 and 3rd as screen is kind of impossible even with docking stations.
I just cannot imagine working in unreal on single screen. Or I rather pick 3 screens over mobility of laptop. So all you work buyers do you really need that mobility?
Do you really work on the go?