The Tamron's bokeh is actually quite lovely--prettier than the 85/1.8 AF-D Nikkor in my opinion. At wider apertures, like f/2.8 to f/4.5, the Tamron 90 compares pretty favorably with many short and medium telephoto lenses.
There are versions of the Tamron 90 that have in-lens focusing motors,and other versions that rely on in-body focusing. Most macro lenses are considered rather slow at autofocusing,and so for action work, or moving subjects, a short telephoto lens will almost always autofocus faster and more reliably and with greater accuracy at "portrait" or 'field" distances. Macro lenses have long,slow focusing throws in the 1:1 to around the 2 meter focusing range--but farther than about 2 meters, and a macro lens typically has an ultra-short focusing range that moves from 2 meters to 3 meters and directly to Infinity in a scant few degrees; this makes focusing, either AF or manual, very hair-trigger at typical portrait and field distances.
For shooting regular,everyday subjects, an 85mm Nikon or Canon lens will work great,even on moving subjects; the Tamron 90 is optimized for close-range focusing,and at longer distances, you might experience mis-focusing, focus hunting, and downright 'missed' focus in a lot of situations where the 85/1.8 will simply nail the focus. This behavior is not particular to the Tamron 90--in fact most macro lenses behave similarly,and establishing precise focus with a macro lens beyond 10 feet can often be a very taxing endeavor; many AF systems will,in fact, ever-so-slightly miss the focus point in continuous AF mode, and in Single Shot AF mode, establishing a focus lock with a macro lens at 15-20 feet can be somewhat challenging on a consistent basis. Not that a modern AF system can not ever focus a macro lens at longer distances--it is just that the "hit rate" using a macro lens is far below that of a regular field telephoto, especially in fast-moving or challenging situations.