From what I've read in the past is that the BHT is a beefier version of the BSTR. Handles more voltage plate etc. Emphasizes more in lower mids and top end shine. It's like the sort of comparing the JJ EL34 and JJ EL34L. One's more slightly beefier and more emphasis on lower end. Email Doug at dougstubes and I'm sure he will explain a bit more between the two and what people tell him.
