I have always been told that "a good worker always has good tools" and that is probably why I always try to be an intelligent customer favoring quality over quantity.
Tying flies does not necessitate a lot of tools so I think it is better to work with a few premium tools than collecting unusable or unreliable ones.
I own two different hackle pliers but I think that the time has come to keep only the best of them.
The older hackle plier of mine is the Stonfo P.M that I did purchase a few years ago to replace an antique hackle plier that was so relaxed it could even not keep closed.
The plier is made of steel which is not of good quality and it has traces of oxidation; it still can pinch feathers stems but there is some rubber coating on only one of the two jaws and this makes this hackle plier almost barely usable for midge feathers whose stems is super thin. The spring which is supposed to ensure the constant tension of the feather when it is wrapped around the hook shank has unfortunately relaxed too much. It is, to me, one more fault of this tool: because of the weak spring I have to remove the trim bag from my vise to use the hackle plier. I do not use it anymore. It is sold around 9 euros, it is not a bad tool but it is not a long-term investment.
Being unsatisfied by this one I decided to invest about 20 dollars in a C&F Design hackle plier because I had already experienced their excellent bobbin holders and I was sure not to be disappointed with the CFT 120M.
This model was designed to work small feathers for small flies (The M in CFT 120M is for Midge) and even though I do not tie a lot of midge kebari I did chose this product because of its small size that allows me to keep my tim bag in place.
The tip is really narrow and slightly curved outward and that detail makes the difference with straight jaws: one can pinch super thin feathers stems without cutting it. Instead of a metal spring like most of hackle pliers the CFT 120M has its two parts linked by a rubber band that extends up to two millimeters. It really minimizes the risk of feathers breakage. The C&F Design tool is shorter than the Stonfo, 65 mm against 95 mm, it is made of high materials so it will work perfectly for long years.
The CFT 120M is a little bit more expensive than the Stonfo but its price is justified by its perfect functionality and the very high quality of the materials used to produce this awesome tool.