Panning a scene with your viewfinder

Tracking, for me, is no issue with an EVF.  I don't find it much more difficult than what I could do with the OVF.  Lag can be slight, but predictable in the majority of situations.

What matters more to me is an PDAF sensor that can keep track of the moving objects I am tracking.  In this area, I find the newer EVF cameras (my A77 included), are better at this than the older Sony OVFs.

While the AF sensor is not dependent on the the type of viewfinder (with exception to on sensor PDAF, which is in its infancy), it just so happens the better ones are equipped on newer models which are only EVF.

So if I had to choose between keeping an older OVF camera where tracking is slightly easier but stuck with an outdated PDAF sensor or an EVF where you have to adjust your predicted movement to compensate for a slight lag but have a better PDAF sensor, I would go for the EVF model.

Tracking a moving object is fairly predictable, keeping a locked on focus to said object is much harder.

--
Paul