</font><font color="blue" class="small">( From some of the posts I've read, guys seem to have bolts and mountings loosening up or coming completely disconnected. )</font>
That's usually on loaders and backhoes from most of the posts, not the tractor. However, this can happen on any part that bolts together, and it's always a good idea to assure that all bolts are rechecked on a regular basis. There is a lot of flexing and other stresses happening when using a tractor, and bolts do loosen up.
Everyone getting a new tractor should check out all the bolts. At the very least, it's best to check the bolts at every 50 hour mark and better to do it more often.
John