John,I get all sorts of shots at all sorts of distances and zoom levels. I normally zoom as far out as I can to fill the frame. Rarely get very close to birds more like 30yards away or very often a lot further.
Therein lies the problem with huge zooms, one tends to use it a lot and you will never get super fine feather detail or low noise at 1500 mm or more. I don't pixel peep, but if I was concerned then I would get a DSLR and good prime lens, but the shots I get with my 1000 are usually plenty good enough for PC or 10X8 prints on a decent printer.
When I switched to the 1000 I noticed an
immediate improvement in image quality, particularly in my garden comparing shots from the 900 and the 1000 all from similar distances with similar birds on the same feeders. Low light is never a problem, if I can see it then the camera will see it more clearly. the huge dia front lens enables me to shoot at F5.6 and 2000mm in good light.
I keep saying it, but the 1000 is an excellent walkabout camera, use as a telescope to scan around, close focus for an ant, manual so easy for tricky foliage shots, peaking to get precise focus for birds on the ground 50 yards away, up to 7fps burst (I mostly do a burst of 3) lovely bright EVF,, decent battery life, image stabilisation and more

I never feel that there is something lacking in use, the 900 manual was a pain in the backside, the 1000 "click and turn" is superb.
I love mine but if IF you want top quality images then get a DSLR, but from what I read on BF no one is ever completely satisfied with their cameras
Den