Yeah, I've been using balsa filters for years, but not with all tobaccos. I like them best with aros, but have used them one in a while with lakeland tobaccos too. My all time favorite balsa filters are the Savinelli 9mm. It's a much different design, gives a bigger smoke, more flavor and absorbs far more moisture. They are a little more pricey, but I usually use them about 3 times, pressing the moisture out with a paper towel and drying them after each use. I only have one 9mm pipe though, a Chacom 2011 POY, and I love it. Large canted billiard with good size bowl. I have used the 6mm balsa filters in my Savinellis, cobs and other pipes that take them, and find they really do work better than the paper filters.
But I still have to admit, for me, that no filter is best about 80 percent of the time.