I have run Shivvers units for awhile, this year I stacked two 10hp fans together and with the wetter corn we are dealing with it has helped a lot.  Seems to dry a lot better.  I run 4 units and the two with the stacked fans will outdo the others.  If you are looking fro a little extra capacity this might help. 

Also, transferring out at 16.50-17% or more and then airing it will speed things also.