Dwtn. Jewelry/Diamond Districts any good?

[GQjordy]

I've heard a lot of negative things about shopping in the downtown jewelry/diamond districts in regards to being dishonest and the scams that they pull. Despite its negative image, would it be wise to shop there if I found a vendor that was honest...If their GIA, AGS, EGL, etc. diamon(s) checked out ok? I mean isn't a certified diamond a certified diamond?

I'm thinking about shopping around in the LA area diamond/jewelry districts and just wanted some imput upon doing so.