In my past experience with testing OLE out, I believe with ACAD2K, I found the following.
1. The background color of the users computer is the background color of the OLE object. For example, I use a light gray instead of the windows Standard White for the background where you type text in Word and Excel. I also use a black font. So the OLE object will print a little muddy when I am the one printing it as compared to someone with a white background. I am not sure if the font color would also change, I doubt it in excel since you color the text per cell. YOu can test.
2. I believe you can only do one page in Word or Excel, the rest gets left off in autocad.
3. If you rotate the plot in autocad, the OLE object does not rotate with it. So if your drawing is set up as portrait and you rotate the plot to landscape, the OLE stays oriented the same it was in portrait. Which will make it off by 90 degrees in your landscape plot.
4. Line weights are harder to control.
5. We need more people who know how to program to use Autosxedule so somebody besides murphy and I will be updating it.
I believe there were other reasons, but it has been so long since i tried it.