Gear timing is a myth, contested but none the less mythic. Oh and Cansoft = clearsoft is a myth as many here have found Cansoft effective in the feild.
Mesh masks are a myth. They will prevent most bbs from bustin through but one hot gun a little closer than expected and you can officially be called a pirate (eye patch, get it, hehe).
Fully metal teath on pistons, they do not help with reducing mechbox wear. They just make a $20 item strong enough to chew up your $70 gears. Replace piston or gears???
Another is that walmart .2g are shit. Yes they are not precision bbs (they are made by cybergun and are biodegradeable) so they are not like 5.97mm with a tollerance of +/-0.01mm. And that means your TBB will probably cry as you slide them through. BUT you can get your stock gun through 5000 rounds under $20 so its up to you, but clean your barrel they leave a residue.