Agreed an end time would be a great help in when we say the rootkit scan should take seconds and not minutes and that would confirm that, or indicate that there is a problem with the rootkit scan that needs further investigation.
I did the ashquick.exe rootkit scan and although I didn't time it there was no apparent slowness. Since we can't say how long the scan after boot takes I can't comment, but I certainly don't see any High CPU usage or noticeable slow down on my system after about 5 minutes after the desktop is up (when I believe the rootkit scan takes place).
No I too have system restore disabled on my system. I don't have confidence in system restore as it can either have unforeseen consequences besides the fact that it often fails, not being able to restore a restore point. I have been using Drive Image weekly disk images for many years now as my replacement for system restore.