I always do a ground balance and noise cancel at the start of a session and regularly through out the day, it takes seconds and doesn't do any harm, so why not?
The article repeats a statement from Minelab that ground balance is not required, but I believe that is taken out of context and if you read the manual fully, the steer is to use it when you feel it is necessary, they even have a section on what the ground noise trace looks like.
The article fails to mention the difference between auto and manual ground balance (auto is perfered). It also also fails to mention that there is no way of determining the degree of soil mineralisation with the manticore (another reason to always to do a ground balance) Note the number achieved after doing an auto ground balance is not a measure of the degree of mineralisation.
With small low conductors, the target trace can be dragged down (and up) by the ground signal, I've seen the trace return to the centre line after a ground balance so I'm convinced it is a must do.
A lot of inexperienced detectorists like to think ground balancing is not required because they don't know how to do it, but I would say if you want to get the best out of your machine learn how to do it and do it regularly! Making it one of your hot keys options is a good idea.