Not tasted it myself, but on behalf of my garden birds, this stuff is brilliant!
I have previously bought the Bill Oddie Garden Friendly feeder seed. Absolutely nothing wrong with that but for some reason I can't get that locally anymore.
Given its RSPB credentials, I bought some of this from my local supermarket and it went down a treat, so I bought two more from Amazon. I'm now seeing Bullfinches regularly for the first time in my garden, as well as a greater variety of other finches and tits.