The same for me. I like most tobaccos at first, then I don't want to smoke them anymore. The ones that pass the test are the ones that I keep reaching again and again.How many bowls have you smoked of each of your blends? For me, I tend to really like the first three bowls of a new blend, and then find out that I don't like it at all. So make sure you give anything you try a fair shot!
And yes you need to try burleys. But I saw you said you like full flavor and rich blends. Burley? Maybe not so much. But you need to atleast try some at some point!