Panasonic mid drive was the industry sweet spot.
Reliable, torque sensing and efficient.
Gave me fantastic range and turned me into one of the fastest roadies around.
In my opinion. Sw may disagree as gutless, D8veh may say overpriced and no throttle!
The Panasonic only gave a maximum of 300w output at the crank, and even lessat the back wheel. That's nowhere near enough power for heavy people. It was the only motor that couldn't get me up the test hill at Presteigne, and I tried two different ones just to be sure. The basic Bafang hub-motors of the time were giving something like 450w at the back wheel, which is 50% more power, though that reduces when climbing. The low power is what gave that Panasonic motor a good range and no problems with gear-changing, so it was also nice and smooth, but, yes, it was gutless.
Ebike nirvana for heavier people is the Xiongda motor. Smooth and quiet while giving up to 600W at the back wheel that's all converted to winch-like torque when you need to go up a very steep hill and it changes down to its low gear. You get all the advantages of hub-motors, like light weight, easy gear-changing and comfortable ride, and the torque of a crank-motor.
For middle-weight riders, the Q128H at 48v and 260 RPM is my favourite. It's the size and weight of a 250w motor, but rated at 800W. With a current control controller, you can adjust the power to whatever level you want, up to an easy 750W at the back wheel for steep climbing. It'll cruise at 20 mph up and down rolling hills without pedalling, if that's what you want, or, turn the power down and ride it just like a normal bike.
For light-weight riders, it has to be the 36V 201 rpm Q100C run at 48v and 12 amps for 20 mph cruising and 450W at the back wheel. It's a great motor for road bikes and hybrids. At only 2.2kg, you can add a 7 Ah 26 cell battery at 1.5kg and have a 13kg electric bike.
For proper off-road riding, it has to be a crank-drive. My choice would be the legal 25 amp BBS01 for self-build, otherwise you can choose whichever OEM one floats your boat.