Take what I say with a grain of salt because I do not have enough experience with these bullets. From what I know or have reloaded myself, campro is probably the bottom bullet. However, the differences in bullets are not great so I would let price be a better indicator of what to buy. I have 3,000 BDX that I am going to reload next week.
I have heard good things about the Zero bullets. XMetal are supposed to perform well but there are a lot of people saying there is a lot of smoke taht burns off as the bullet goes down the barrel. This is because of the coating on the bullet. I do not buy them because being made in Quebec and X-Reload being the supplier I would normally use, the price for shipping starts to be difficult to want to eat. Some barrels like to build up lead deposits from lead bullets and some do not.
BDX claims he is a good shooter but that does not necessarily mean he can make a good bullet. That being said and with cross comparisons to the Campro, I think the BDX bullet is a bit more consistantly shaped and that should result in better bullets. They can be hard to find in some regions, just like Zero and XMetal are. Campro are sold everywhere so they become the standard to beat in most cases.
You may well have greater gains in accuracy by working with different reload recipes than changing bullets. I would rank my choices of bullets in the following way because of price, local availability (alberta), consistency in construction etc. The differences in accuracy are not that pronounced as to make a clear winner that way.
BDX (easier to get in AB but maybe hard in Ont, QB)
Campro (easy to get anywhere and a go-to standard)
Zero (easier to find in Ont and QB. Supposed to be accurate for more recent buys. A decade+ ago had some issues in the builds) (perhaps the most consistant now).
XMetal (expensive after shipping to AB and smoking issues)
BDX may fall near the bottom to the folks out east because of difficulty in sourcing them and extra costs to shipping. They are still good due to their consistant construction that lets you build a good reload recipe and get consistant results. I personally use BDX and Campro but I have brought in some of the led bullets to compare with because accuracy is a big issue with me and I always compare bullets every 3 years or so in case anyone has made big strides in accuracy. No one really stands out to me in a big way although I would still put BDX first and Campro last for accuracy at least.