RE: Just did a manual update...
The update install process (mafapx.exe) should not take over the system to the extent it is not usable for so long (the download should not be resource demanding), however the CPU time consumption during the installation of the update is relatively high, of course. AVG update process uses the MSI installer technology. Should you face the situation again, please provide us with more details about your system, preferably an msinfo output uploaded to an online storage service.
The guru.avg.com is a free update server. Although the performance is quite good, it may feel slow during peak hours. Paid-for versions do have access to Akamai high speed network. Unfortunately, the costs for transferring data over this network is quite high, so we are not able to provide the access to it for free users.
Unfortunately, I don't have a full list of AVG file names. Such a list would anyway get obsolete soon, as there are added new files with new features during AVG program updates sometimes. Generally, many of the AVG files have the "avg" string in the beginning of their name. AVG files are digitally signed by AVG certificate, so if unsure, check the digital signature please. If you find a suspicious file, please send it to our virus analysts as described in the What to do when I suspect any file it is infected? article.