Brickseek is slow, useless and tedious.
We are talking about a site that you put in your zip code and it shows a map of your area.
What the OP is talking about was a site I think was called idevicechecker or something.
It specifically showed Apple Store, Best Buy and Target stock.
Not sure what happened to it.
I don't think it was 100% accurate anyway but I was able to use it to get my 6S plus last year.