I read somewhere, but forgot where now. Anyway, it said that loop connections were fine for 5wt and above. It said a nail knot is better for smaller lines to get a good turnover. It kind of makes sense, but i'm not sure if it's true. It also talked about the lower lines were using much longer leaders than the heavier lines.

So, since my main interest in small streams with light lines and probably long leaders. I might be better off with a nail knot and a good match from line to leader butt.