It seems that these "super-zooms" often are better in the mid zoom range (in
this case at 20mm)
than the corresponding prime lens. Probably because of more time spent on
development and
use of expensive glass etc. I sold my AFD 24/2.8 after I got the 17-35 zoom
which I use as a
variable 24mm lens :-)      ......the 12-24 will be a pretty good 18mm lens
even at a full frame body
I hope.....

Yuck!  I'm a Diet Coke and NY Strip man myself.
Had that exact thing at Outback last night, in fact.

I understand that you back up your end to a lot of guys.
As for me, my mouth don't write checks my a.s can't cash.

Rita is exactly right about getting rid of digital bodies on-time.  It is
not always exactly 18 months though.  Up to the announcement of the
replacement model for you body, you can sell it for a significant fraction
of the full retail price, possibly up to 80%.  Within a week of the
announcement of the replacement model, the used prices fall quickly as the
market suddenly gets many used ones.  Then it is too late.

The most important part of "buy low, sell high" is "buy low".  You have to
make the money on the purchase, not the sale.  If you were really shrewd and
lucky in the purchase then you can sell it after using it for 18 months or
so of having a current camera for close to your purchase price and the
camera has cost you next to nothing.  Then you can buy the new one which
won't cost much more, or even less than your old one and still get to use a
current camera.  You always get to use a current camera body without much
additional cash outlay.

This is even more so with lenses.  They often sell for 80-90% of the price
of new _in your area_.  This seems attractive to buyers since they don't
have to pay taxes on the used lens and most don't want to deal with
shipping.

However there are much better prices available for those willing to shop
around.  Canon USA refurbished lenses, which I find to be better than new,
sell at Adorama for almost half what lenses cost here in the big box stores.
This means that when I am done with a lens, I can easily sell it for enough
to cover the cost of the lens, hood, shipping and taxes.  Fluctuating
currency rates, particularly the very low US dollar and finding the cheapest
shipping make this a good deal. There is no duty or excise on imported
camera equipment here, just sales tax.  Used lenses here still seem to sell
based on a fraction of the current local store prices which Canon hasn't
adjusted.  Sigma lenses seem to lose value in the used market a lot faster
though.  It makes financial sense to by Canon branded lenses.

This makes digital photography almost free other than the loss of interest,
opportunity and inflation on the money you have tied up in whatever you
presently own.

Clean them up and dump them.  There's no sense in warehousing equipment you
aren't and probably will never use again.  Convert them unwanted lenses to a
nice new Nikkor that you'll use almost every day.

Rita

Ah, OK I see how that makes sense. I have a 30mm medium format fisheye
and made a rig to do that with, though I'm not sure I'd have the need to
stitch a huge fisheye poster... I use it more for tilting the focus plane.

I haven't seen a ZM 15mm Biogon, let alone tried one.  Nor have I
tried a ZM 85mm f/2 Sonnar.  But I have tried all the other ZM lenses
on an M8 body, including some comparative tests with Leica lenses of
the same focal lengths.  The ZM lenses are outstanding performers on
the M8, and they have no need of the Leica 6-bit coding.  I expect the
ZM 15mm and 85mm lenses will be equally impressive.

Until 2007, it was the best 21mm lens for Leica M - obviously, it has
to be used with an adapter.  The new Carl Zeiss ZM C Sonnar 21mm f/4.5
is a modern interpretation of this classic design, and not only does
it display near-zero distortion, but it is sharp right out to the
corners, even wide open.  An outstanding achievement.  For me, this is
easily the best new lens of 2007.