It burns you out two boxing two runs at the same time every day so I would often just run one alt through (which is actually relaxing instead of annoying) or take a night off now and then to do other events. I play more casually than I used to, and usually only on for max 3 hours per evening.
I agree the average is around 120 alex per run. I believe the best legit way is to do both salvage and dynamis each day but damn me if I want to torture myself that badly...