Even 1TB isn't enough for me these days, especially since Lightroom requires your catalog be on your boot disk. But 2TB and 4TB upgrades, in addition to a cost

Even 1TB isn't enough for me these days, especially since Lightroom requires your catalog be on your boot disk. But 2TB and 4TB upgrades, in addition to a cost of I think $400/$800 respectively, require you move up a CPU model as well - a HUGE increase in cost that most users can't justify through improved performance.