The rubix cube that is the XX4 needs all sorts of jiggling and manipulations to even get to the belts - by that point half the screws are lost in the grass and your 12 minutes becomes 45 + plenty of sweat and swearing.
I've no idea how long it takes to change a 501X belt - maybe just as long since the top decks etc all need taking off. But it doesn't feel as long since you're not swearing and in tears -and I base that off personal experience
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