Really depends on which computer you currently have and what you're comparing it to. Of course there's a speed difference across the board, but whether you'd perceive it is entirely down to your work. If you are finding your current software slow and sluggish then yes you'll see an improvement, if not then it's hard to say.
Generally speaking they'll be about 20-40% faster in day to day usage, things like opening apps, transferring files, general OS usage etc. Top end you could be looking at upwards of 50% faster, which makes things like rendering or transcoding significantly faster. So things like gaussian blur should be noticeably faster for you, as well as opening a PS file. But probably not adding layers and painting over stuff.