bigal,
The nature of all the PCLinuxOS versions is that the packages are updated as they are available from the original developers. Some are improvements, some are security issues which have a patch, some are bug fixes, etc.
Even though your XFCE may be relatively new, there's been numerous updates over the last few weeks. If anything in any of the original packages has changed, after your install, the first synaptic update will bring in and update all the packages that changed.
So.... the number of packages updated is a testament to the hard work of the PCLinuxOS development team.
Not sure on the speed test package you seek. I donate so I have PASS, so I don't worry about which repo I use.
Enjoy,
putz