The Samsung Focus comes with 8GB NAND memory whereas the HTC HD7 comes with 8GB NAND (presumably) and an 8GB microSD card. Of course the Focus can be upgraded by adding a microSD card, but it does not come with one. The theory has it that the HD7 will probably perform slower due to the memory card and indeed, in our tests, this is the case.
Overall, the Focus feels faster in everyday tasks, navigating the UI and of course loading Need for Speed Undercover, in comparison to the HD7. But, that may be due to the Focus not having an SD card. Either way, the difference is obvious in this video.