To someone with experience a torque wrench is not essential but to someone with limited or no experience i would think a torque wrench would be beneficial . especially on things that if loose can cause stability issues like axle nuts . A torque wrench can also be a dangerous tool in the wrong hands that could easily lead to stripped threads especially if they are already worn,damaged or greasy .There is no substitute for " Touch" and that is the only way that experience can be gained . a few years ago i bought a yam as3 125 and i decided to change the plugs after much struggling with the plug spanner i attached a short length of car exhaust pipe to the spanner and hoped like hell that the plugs wouldnt break off in the cylinder heads anyway they didnt and they finally came out, which gorilla put them in god knows but those sort of people shouldnt be left alone with tools in a workshop