I am not a fan of Diorshow Blackout because of the huge wand which made it difficult for me to apply it to my lashes only - without ruining the eyeshadow on my eyelid! Also, Blackout didn't curl either. But, guess what? I LOVE Diorshow Iconic because of its wand with soft, cleverly-placed bristles: it lengthens and gives amazing curl! It doesn't clump and lasts day&night although it's not waterproof. The lashes are easily coated and they're left soft the touch.
I've got very fine lashes, medium length I guess, which could do with a thickening mascara. Iconic might not thicken like others, but it does so much to my lashes and it looks so classy & dramatic at the same time, that I absolutely love it!
Just as a reference, mascaras that didn't have much effect on me: Maybelline Great Lash, No 7 360, No 7 Great Lash, Estee Lauder Illusionist, Diorshow Blackout. Of all the pre-Diorshow Iconic I ever owned, the one I liked was Clinique for Great Definition Lashes (the one with a comb included in the bristles). In my opinion, it's all in the brush!
So, if you've had similar experiences with me, it's very likely you'll really like Diorshow Iconic.