That's great to hear .Ok, feedback time!
I will sort-of double post here, since the feedback regarding the diamond file came from this topic, but the depth gauge feedback from another topic....
Anyway, having filed the half-used 3/8 Stihl full chisel chain (which cut very well to begin with), I finished each tooth off with a couple of swipes from the Trend Diamond File in 600#. The teeth were "sticky" sharp. I then used Hannes69's progressive depth gauge to drop the depth gauges to their new level (in order to maintain that constant cutting angle of around 6 degrees). This chain ate wood like a pitbull in a Barbie Doll store!
I literally could hardly "feel" the cutting taking place. The best way to describe the sensation would be that the chain "melted" its way through the wood. Admittedly, I only took down a small bluegum (around 8 inches ion diamteer, and about 20' tall), so the wood was really soft (as opposed to the more mineralized fibres in m,ore mature trees), but the chips were flying! My BIL commented that he had never seen such nice big chips flying like that. And to top it all off, the chain was very well behaved - not "grabby" or rough at all! I did not try a bore cut (this normally exposes a too-low depth gauge setting better than normal cross-cutting), since the tree diameter was too small, but I am convinced it will be really well-behaved!
I was initially rather cautious about the large depth gauge setting (this chain is past its halfway mark), but my fears proved unfounded - it really cut without issues!
Thanks to all who helped get me here!