I did get a chance to range some deer this season. The farthest it ranged deer was around 600 in poor ranging condidtions. Deer up to 900 in good conditions. I think that it would do better but I only hunted deer for 2 days and all the deer were in tall grass or laying down. Also a tripod or good rest would increase the ranging capability. It does not range light colored grasses very well though, 600 tops. It does however range trees and rocks really well, In bright daylight 1150-1250 on green trees and rocks is common. At dusk up to 1400 on trees and rocks. Brown clored dirt was not bad I could get readings of 950-1100yards. I would guess that your white colored target would range at least 1300 in daylight. I ranged 1320 on a white garbage truck in daylight.
I thought it was letting me down this year at one point. I tried and tried to get a range and the only readings it would give me were around 650Yards. The only probelm was that I was shooting across this field that was supposed to be half a mile across (according to the landowner). So I decided not to trust the range finder and dial in for 880yards. I shot and did not see any signs that the bullet hit anywhere even close. The deer didn't move so I dialed back down to 650 and shot into a near by dirt bank (probably what I should have done the first time). It hit right where I aimed, so back over to the deer that still did not even get up. Bang and dead.
Overall it seems to be a good unit for the price. I really like how fast it gives a reading back(Almost instant). The elk have come down for winter now so I should be able to spend some time ranging them to get a better Idea of its capabilities on animals. I got my elk in bow season and it had no problem ranging that elk at 14 yards /ubbthreads/images/graemlins/grin.gif