xft horizontal spacing

[Aron Griffis]

I've just started using rxvt after years of using xterms.  One of
the first things I've noticed is that xft horizontal spacing is
different:

http://agriffis.n01se.net/misc/rxvt-monospace-9.png
http://agriffis.n01se.net/misc/xterm-monospace-9.png

Personally I like xterm's tighter spacing better, and it matches
what I see in other applications (gvim, gnome-terminal).  Can
anybody explain this oddity, and if there's a way to change it to
my liking?

Thanks,
Aron