CNet and The Inquirer have Intel's response to PC Perspective's alleged SSD 'slowness' claim:

CLAIM: A laptop user placing light workloads on their X25-M may never see the worst of these issues, but many users are going solid state for their desktop OS partitions, and a typical power user workload can fragment these drives in short order. It is likely that other manufacturers will employ similar write combining techniques in the future, and with those new devices may come similar real world slowdowns. While the specialized controller used by Intel enables it to bulldoze through most scenarios, we have seen that even the best logic is subject to severe write combining / internal fragmentation. Hopefully Intel can further tweak their algorithms with a future firmware update to the X25-M. In the meantime, we hope our suggestions keep your SSD on the speedier side of things.

INTEL's RESPONSE: "Our labs currently have not been able to duplicate these results," Intel said. "In our estimation, the synthetic workloads they use to stress the drive are not reflective of real world use. Similarly, the benchmarks they used to evaluate performance do not represent what a PC user experiences." Intel continued. "In general, when a PC's drive (SSD or HDD) is full, there will be some reduction in system performance, however the performance reduction reported by PC Perspective is higher than we generally expect, which is why we are looking into the methodology."