I heard that there are some arcade machine operators/manufacturers who like to use harder (i.e. require more force to activate) spring since they believe that it will reduce the damage to the microswitch, etc. if newbies slap the button VERY hard. The "hard" way of playing means the same thing: get more used to a 400g setup than 200g. The "arcade combo" is basically a "Sanwa LHSXF+button+200g spring" combo since that's the default setup for an official arcade cabinet. I see. So my assumption is completely wrong. I thought that you might just simply prefer 400g springs over 200g.