While going Intel can improve your performance, you have to balance it against the additional cost (Intel CPUs run higher in cost than AMD CPUs), plus having to buy a new motherboard (Intel CPUs don't fit AM2/AM3/AM3+ sockets, & vice-versa), plus the extra time & hassle of having to reinstall Windows from scratch.
You will see a little bit of a boost going from the FX-6300 to the FX-8350, but not a whole lot of boost. You might see the same (or even better) performance improvements if you get an aftermarket air cooler & OC your 6300, but it depends on how confident you are about OC'ing it.