Probably the most important thing to consider when researching the best electric touring bike for you is how far you need your bike to take you every day. Be realistic about this. If you purchase a lower end electric bike, don’t be surprised when it only takes you half as far as you want to go. Think about whether or not there are going to be opportunities to charge your battery in the middle of your daily riding. If not, it might be a good idea to buy an extra battery.
E-bikes mostly use motors and battery options from a few major suppliers: Bosch, Yamaha, Shimano, and Brose. A few other brands exist, but are less reliable or powerful. Some, like the Yamaha system, have more torque and others are quieter. But generally all four make good options. Look for motor output (in watts) which will give you an idea of total power. But watt hours (Wh) is perhaps a better figure to use—it takes into account battery output and life to give a truer reflection of power.