Upload & Sell: Off
I haven't tried any Heliopans, but have a few B+W and cheaper Tiffen ones.
Frankly, I don't feel their is much of a difference between the two, since all the ones I have work perfectly fine. I tend to not over-tighten them, so my experience may be different then others.
The B+W have a better matte finish to the Tiffen shiny finish - but it really doesn't matter to me, as long as they work.