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.