I agree, void is not any faster or slower than other distributions it you 
look at raw performance. On the other hand, running a streamlined void with 
a lightweight window manager will of course feel much more responsive than 
an Ubuntu with Unity and 100 daemon processes that do who-knows-what in the 
background all the time, especially on older hardware.

If with "just works" you mean a distribution that is easy to install/update 
and provides or at least supports everything you may ever need you will 
have to go with Ubuntu since that is pretty much the only disribution that 
has achieved some mainstream traction. There are several softwares out 
there that are (officially) only supported for Ubuntu. If Ubuntu itself is 
too bloated for your tastes try Xubuntu <http://xubuntu.org/> or Lubuntu 
<http://lubuntu.net/>. You can even do an Ubuntu minimal 
<https://help.ubuntu.com/community/Installation/MinimalCD> installation and 
customize everything just as you would in void. Thats what I'm using on my 
laptop and the performance is just fine. That of course might impede its 
ability to "just work" though :)

Using apt for package mamagement is not as fast as xbps but also has a lot 
more packages to deal with. void currently has about 7000 (very rough 
count, factoring in meta-packages and 32bit versions probably substantially 
less) while Ubuntu is approaching 40000. By the way, Debian 
<https://www.debian.org/> has even more packages (approaching 50000) but 
somewhat lacks the mainstream traction. It might be an option for you 
nevertheless.