I have really never had an issue with a CPU/GPU/RAM on a refurbished product slowing a system down, all i buy is refurbished products usually, my main concern usually is a hard drive that isn't corrupt, damaged ports, damaged screen (dead pixels), damaged keyboard. These are issues that i have found to be the most prevalent in refurbished laptops. regardless of new or refurbished, the laptop will usually be slow at first because of bloatware, once uninstalled, everything should work in a normal fashion with updated drivers. also be sure to read the return/exchange policy and whether it is seller or manufacture refurbish.