New memeber here, but I wanted to comment on this topic:

I had several experiences a couple of weeks ago while using my new Double Bull blind that convinces me that the birds definitely do notice and will be leary of it if it' s setup the morning of the hunt, brushed in or not. While I also believe there are exceptions, I' ll be setting it up at least 3 days before I plan on using it!

Good luck to all.......

J