ORIGINAL: Wing-and-a-Prayer
I dunno, guys. I just talked to Horizon Tech suppt. today regarding my 6000 and the 6100. They are both "parkflyer" recievers. I was thinking of the 500 as well when I asked him just what is the actual range on the 6000 and the 6100. He told me the range was 600' to 1000'. Six hundred feet is 3 football fields. If you think about it, a parkflyer can become pretty small that far away, so 1,000' seems pretty adequate for most "parkflyers".
FYI, 600' is only 2 Football fields.
I only mention this to help your prespective and depth perception.
I use the 6100s with a DX6i in foamies that I've taken high and far enough that they're only a speck in the sky and had no issues at all.