Marginally / "Depends".
More memory and CPU time aren't going to affect loading of pages; bandwidth is the bottleneck.
However, if you're playing lots videos, or have multiple tabs/windows open with embedded media, it's feasible that the speed up would be more noticeable. This is especially true if you had a low amount of system memory to begin with, and after the optimisation your browser could use more memory rather than pagefile.
(Of course, if the optimising process removed applications that were using a lot of bandwidth, then yes, the difference will be very noticeable).