Compared to the older C300, Crucial's m4 SSD is more of a shift in performance priorities than a new design with improved performance all across the board. We see substantially improved performance in scenarios like Large File Copy and Game Patching. On the other hand tests like Windows 7 Startup and Photoshop Startup run slower than on the C300. It seems to me that Crucial has taken the existing firmware and turned some magic knobs, probably based on good research, to improve performance for their typical user profile. Based on our benchmark results I'd say that general performance has really increased, whether this is true for you depends on the tasks you perform in your daily PC usage. Most office and power users turn on their PC once a day or leave it running overnight, so Windows boot time might not be that important to them. Other users tend to have shorter work sessions and shut the PC off in between, so startup time is more important for them. I guess when looking at C300 vs. C400 performance it comes down to your own usage models, but fear not, both drives will give you substantially improved performance compared to a traditional HDD. When looking at pricing, the battle is a decisive win for the older Crucial C300, the 128 GB version comes at 200$, while the similarly performing m4 128 GB retails at $250. Considering that the m4 uses similar hardware, I see no reason why Crucial couldn't sell the m4 at C300 levels in the future, at which point the drive would quickly be able to capture major market share - the C300 is the best price/performance and GB per $ drive on the market right now.