I have had an FZ20 for the last seven months, and a 20D for
a little over a month. Bought both for long zoom, and shooting
birds, so my experience may be irrelevant to you depending on
what you use a camera for. Since I got the 20D, the FZ20
has been retired as my birding cam,
but I find that has freed me to use the FZ20 more
for casual shooting and macros -- my 20D is my dedicated birding
cam and the FZ20 for everything else (eg I rarely switch off
the 100-400mm long zoom lens on the DSLR for a 17-85mm,
instead using the FZ for that range of focal lengths).
Haven't done much low light photography, though the DSLR
handles a wider range of lighting conditions better (given my
current level of skills; others can probably do better).
I think that each person has to decide what combination
of features suits them best. DSLR has vastly better image quality
but at a cost in dollars and weight and inconvenience. The FZ's
do a lot in one package for a lot less cash outlay, but the noise
washes out details (in my photography, I see it in feather detail
of the birds that the DSLR captures and the FZ does not).
That's my experience. Other people shoot other things and
have different criteria. Just my $.02
--
emil
--
http://theory.uchicago.edu/~ejm/pix/fz20/bird_galleries_2005/
http://theory.uchicago.edu/~ejm/pix/20d/20d_birds/