Yes - I have! 100% authentic bags. Never heard of anyone having a problem with authenticity. Use caution about their return policy - sale bags are store credit only upon return!
I ordered the black patent natasha from them yesterday. I was bummed because I saw the holiday coupon for $100 off from $400 orders or more...it said "expires 12/20 at midnight." I was bummed because it was 12/21 at about 10:00am. I called them and asked if it was possible to still get that discount and she said yes! So...I got her for $525.00 flat! Loves it!
I visit jcmadison from time to time, oogling at the eye candy, although I've never made a purchase. Now that I know they are authentic, I might just have to splurge.