Rhine River East to West

The Rhine between Basel and Mainz could be just about any river in the industrial world. The scenery is not particularly special, and nearly a mirror image on each side. North of Basel, the Vosges mountains in France are on your left, and the Black Forest of Germany are to the right. Both are about the same height, and I'm not sure if you can see one better than the other from the river. North of Karlsruhe, I might give the left bank a slight advantage, because there's nothing particularly interesting to see on the right (the Odenwald mountains are scenic, but you can probably barely see them from the river), whereas you'll get a good view of the massive cathedrals of Speyer and Worms on the left bank. Of course, the massive chemical plant on the same side by Ludwigshafen probably represents the single ugliest thing you'll see on the entire trip. Until you hit Mainz, the left bank continues to be marginally more scenic (vineyards as far as the eye can see), then the Wiesbaden side is more interesting until you reach Bingen. At Bingen, you enter the Mittelrhein, and although I think the left bank offers the better views, you will absolutely not want to stay in your cabin for this stretch of the river! There's a brief ugly industrial area north of Koblenz, then the river is fairly pleasant on both sides until Bonn, where the left bank offers more interesting views. Downstream from Bonn, it's mostly just an industrial river again.

Thanks for that detailed reply!!
I chose the left side for your reasons, but also because that side of the ship will see the sun (in Sept.).
Thank you again!!