There's a lot of different transient shaper plugs out there, but there are two fairly common models that seem to dominate the scene. The two knobs model (adjust the volume of the attack and sustain) or b) the one knob model (it does fat and thin). Clearly Bittersweet falls into the latter category. Sure you can alter the speed and the length of the effect. But generally I find the default does a pretty good job, and you're only likely to gently tweak the settings, if at all. Bittersweet sounds as good or better than other transient shapers I've tried. Those other ones cost money. So the choice seems pretty easy.
Occasionally I've seen this crash my daw for no good reason, otherwise I would have rated it higher.