I do - for the past 6 years. I use Barlean's Ultra Potency and Nordic Naturals Complete Omega lemon flavored liquid. We also use the gummies when I run out of the liquid supplement and need to re-order. I buy the Barlean's from the local health food store because it needs to be refrigerated.
I have not seen any visible changes in my kid (except he does not have the dry skin condition he used to have before he took it). I figure that it will keep his heart healthy even if it did nothing else.
I have always used the high potency omega 3's. I don't have any specific reason for choosing the high potency omega 3's.