It's all of it, but not necessarily in equal measure. If you are buying for research or to sell on you start with the knowledge-based gut reaction then add in the assessment before yay or nay. Here the assessment is important and can mean the difference between loss and profit, buy or leave. If you are buying to keep, you start with the heart-based reaction, then you consider the knowledge-based assessment. If you don't care about its failings that's fine.
Yesterday I bought a horrible brown, vaguely streaky looking paperweight. My knowledge guts knew what it was before I assessed it, but I'm never going to love it. It's a Malta Decorative Glass PW with a label and sand-blasted for Malta Insurance Co. Ltd, neither of which I could see before I knew I was going to buy it. It's uncommon and a research item so it will stay.