General paintball rule with regard to gun upgrades. If it aint broke, don't try and fix it. Always try and establish if there's anything wrong with your current gun?
Because of the mini/axe popularity there's been a massive business that's sprung up around upgrades and replacement parts. A lot of them are either expensive snake oil bull**** or require a considerable amount of faffing to get working at their best (which can often be knocked out of whack during maintenance and climatic conditions). Some people will swear that dropping in X or Y part will lead to INSANE shot efficiency, increased life expectancy or felatio on demand but it's mostly all garbage.
I've been doing a lot of reading into the Axe/Mini platform due to picking up a D*Fender recently and the conclusion I've come to is that the stock internals are great, maybe spend a bit of time on tuning what you've got but just keep it well maintained and it'll shoot great and have enough efficiency for any normal person.
