By 'torque sensing' I mean from the pedaling input from my legs or arms to invoke and direct the motor response.
I spoke with a fellow riding a recumbent trike, and he liked the torque sensing as that way he could just 'push off' and the motor helped from a stand-still. A cadence sensor won't register until the crank, and hence the bike, has moved some ways. This can be difficult from a stop facing up hill - worse if I didn't down-shift in time (red light, surprising traffic, kids).
I have a recumbent trike and I don't have a torque sensor - I do have a high-resolution cadence sensor (24 pole). I often use the throttle to get started from a stand-still, and this is legal in some Australian states for that reason.
In general, a throttle-controlled electric bicycle or tricycle is considered to be an electric motorcycle here and will require inspection to safety standards it will never meet plus compulsory insurance for road use. Off-road or actually off-regulatory-scheme venues such as farms, some parks, natural areas, etc. don't regulate a throttle. All footpaths (sidewalks), shared paths, bicycle paths only permit a throttle in some states for starting from a stand-still up to 6km/hr (walking speed).
I think a torque sensor to invoke the motor can be useful.