After weathering the first SSB contest with my new (last October) K3s, I have 2 comments: awesome filtering(!!) - was able to mostly kill strong stations unless they were 500cycles away and really loud and splattered, and 2 - I wish I could adjust the manual notch width!
On the notch, there are some instances where tweaking the width a tad wider could cut some interfering nearby stations enough to make the target station legible. Then there are occasions when the manual notch is too wide when an offending tone is right up against the target and the notch cuts into the target station (auto is way too wide). My old IC-7600 and 7700 had that feature and could really help out on a crowded piece of band.
Any chance the adjustable notch width might be in a new software release?