It's an interesting question on aluminum chassis vs Manners elite carbon fiber type stocks. If you look at the list of what gear the pros use, there is a mix of both in the top 10. The number one spot has consistently gone to Manners over the last few years though. Does that mean that carbon fiber stocks are better or does it just mean that people look at those lists and try to buy the same gear as the guy that got first place last year? Who knows.
As a general point, carbon fiber parts are stronger and stiffer than aluminum by weight and volume. Important qualities in a stock. If made right, they also have superior dimensional stability with changes in temperature. The "if made right" part is key though.
I enjoy making my own carbon fiber stocks for personal use. Lately I have been wondering why nobody makes a carbon fiber chassis system. I generally prefer the tactical looks of the aluminum chassis systems and I like the idea of being able to switch out the grips and stocks etc. I would like the being to get the benefits of both. I.e. A strong, stiff, lightweight, modular, cool-looking cf chassis system.
I think that, at the top level, the best shooters can probably perform well with any of the stocks or chassis systems used by top 10 participants. In other words, neither is superior if they are both well made. They are both better than wood stocks.
I really like the looks of the Masterpiece chassis systems.