I had two shivvers units with computer controls, liked them a lot.  Only drawback I had was speed of drying, but the newer two auger on the floor systems would be a lot faster, I would imagine.  I had a single auger with 4" crossovers to five bins, could dry about 200 bu per hour, a lot when we had two and three row heads.  When we got 6 row heads, I bought a set of bins with another shivvers unit, could fill one, then go to another, worked almost as good as a continuous flow.

Another drawback might be wear and gearboxes under corn going bad, but I never had a problem.  Make sure you maintain gearboxes EXACTLY according to instructions once a year (with your acreage) and you should have no more problems than a continous flow.

I know many will argue with the above statement, they guy who bought my set-up junked it and went to a continous flow, but he had a much larger head, and did not want to ever wait on the dryer.

There are enough safety switches built in that you don't have to worry about them.  I run 4 of the older shivvers units in order to keep up with an 8r head in 200 bu corn.  Three of them run most of hte time and the fourth is used on a good day when we put out a lot of corn.

You don't have to babysit them.  When we are dumping we look at them of course, but at night we will check them at 10pm and then at 5-6 am.  The ideal situation for it is if you can have a wet holding bin so the depth of corn can be kept to a minimum in the drying bin.

We have run these for 20 or so years and have only had one gear box problem, it was on a Neco system(same as shivvers)  And we had a piece of flighting come loose on a vertical auger, other than that the mechanics have been fine.

If you end up going with a shivvers put the moisture sensor in the horizontal auger that comes off of the center pole.  There will be a lot less wear on the tube and flighting doing this.