http://www.dpreview.com/reviews/compare_post.asp?method=sidebyside&cameras=n
ikon_d50%2Cnikon_d70s&show=all

Hope this helps,
ink

    I presume that this means that the lenses which you already have
are CPU equipped.

    Someone else already posted a pointer to the reviews of the two,
so you can compare them in detail.

    I will simply say that it depends on how *technical* your
photography is.  It is is not very technical, about all that you will be
missing is the brightness of the viewfinder -- and no button to turn on
a backlight on the display on the top of the camera used for quick
settings in low light conditions.  There are always the menus, but they
are slower to use.

    The more you leave the camera to its automatic selections, the
less important the differences between the D70s and the D50 will be.
The more you want to control what it does, the more important the extra
features of the D70s will be.

    Both the D70s and the D50 have larger displays for the menus, so
that should help.  And the D70 at least has a thumb slider to control
diopter correction of the viewfinder.  (I presume that the D50 has this
as well, though I did not look for that when I examined one in the store
while picking up other things for my D70.)

    Personally, I would go for the D70s if I were buying now (and if
I could not afford the D2X, which is what I *really* want. :-)

    I have used all of the features which the D70 has and the D50
does not, so I think that for *me* the choice is clear.

    Best of luck,
        DoN.