Changing suspension settings to suit your height, weight and riding style on almost any bike should give you a big handling advantage but it depends on a few things.
If the settings have never been changed chances are you can get the bike a fair bit better to suit you.
If the previous owner changed the settings consider if he/she was similar to your height and weight. If they were it might be close to it\´s best already. If not you might be able to make a world of difference.
Haven\´t had any real hands on experience with changing the settings but if you know what you want your bike to do different or better any mechanic worth his/her salt should be able to tell you if it is worth doing.
Hope this helps and sorry if you already knew some/all of this. 
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