I ride all three of my bikes without a top case while commuting. I only use a top case for long trips.
The width of most saddlebags is less than the width of your mirrors and weight up high and in back is bad riding physics compared to down low.
I don't even have a top case for my 800GS yet. I have a luggage rack that I strap a dry bag to for long trips, though. Don't feel the need for one at all.
2011 Husqvarna TE310
2009 BMW F800GS
2007 HD Road King FLHR
2003 Husqvarna TE610e
1997 BMW K1100LT Special Edition