I just got a 2005 Forester XS.
I was considering the 2006 models, but the 2005 XS was definitely better for me.
First of all, I'm 6' 5". That means that I cannot abide a sunroof, because it takes away precious headroom.
In 2005 models, I could get an X or an XS with no sunroof.
However, in 2006 models, the XS had been dropped, and only the X can be had with no sunroof. This means that I would miss out on certain mechanical features unavailable on the 2005 or 2006 X (like the limited slip rear differential), and a list of convenience features.
So, if you need a Forester with no sunroof, check out the 2005 XS while its being cleared out.