Very reliable, but more reliable then expected. My brewing software, Brewfather, had this entered at 75% attenuation. Noooope. Expect over 80% attenuation, perhaps even 85% attenuation. My target FG 1.011 Irish Red Ale ended up at 1.005. My software and brew performance on my equipment is very tuned and consistent, so the yeast is definitely the outlier (the high attenuation level has been confirmed on several homebrew forums).Be sure to check your software's expected attenuation for this yeast and adjust your temps or non-fermentables accordingly.