I haven't paddled tandem in decades, but I have a lot of differently shafted and bladed paddles when I paddle solo: straight shaft paddles with both flat and spoon blades, single bends with both flat and spoon blades, double bends with spoon blades, double scoop dihededral blades, and S-blades with various bend angles. I have straight paddles with varying blade shapes—from otter tail, beaver tail, Sugar Island, Honey Island, to tulip-shaped racing blades. On top of this, I have paddles of different overall, shaft and blade lengths, many different weights, as well as constructions from different wood and composite materials.
Each paddle has a different feel and takes a while to adjust to. I can paddle with any one of them productively, but have favorites for different canoe hulls and different water and wave conditions. I can't see offhand why anything would be significantly different if I were paddling tandem stern instead of solo. I'd probably develop favorites.
You likely would become become more comfortable and efficient with the Werner Bandit if you became more familiar with it by using it more in the stern. That doesn't mean you'll ever prefer it over a straight blade. Offhand, I can't think of any particular reason why an aggressive spoon blade would be preferable for me when paddling stern in recreational flat water or quiet water.
I can see a power advantage for acceleration bursts and dynamic draws in whitewater paddling. I can also see power advantages for flat water canoe racing. Both marathon canoe racers using bent shafts and Olympic high kneel sprinters using straight shafts have spoon or curved blades.
Lots of people who paddle at a modest recreational pace, especially if they have shoulder/arm/wrist problems or as they age, don't really want to paddle long distances with an aggressive blade having a strong and powerful catch and pull, such as the spoon and curved blades usually offer. Many paddlers may be able to perform a J or rudder correction stroke more easily with a straight rather than a curved blade, which can be important in solo and stern paddling.
