So-called 'soft bipolar' seems an attempt to categorize traits (note I did not say "symptoms") whose frequency and severity are a magnitude or more less than for full-blown disease states. Since in bipolar it is the manic component that gets the patient into social and personal difficulties (the depressive states are primarily painful, and disruptive only to the extent -- all too real -- of pre-emptive prevention of exposures via acting out and similar behavior) many in the field choose to call the less than diseased states as "hypomanic". Neither of these terms, however, is either correct or appropriate in my view.
The trait-based nosology (see my paper on the subject ,http://ssrn.com/abstract=1652925) recognizes that the trait prevalence exists on a continuum in which manifestation of primary traits at sub-severe levels (disorder and disease should be the two categories of so-called 'major' conditions) typify the "bipolar personality" in which the traits are disposed from an ingrained "character" reflecting a genetic disposition to manifest trait combinations redolent of the more severe expressions of disorder and disease).
In this trait-based nosology, therefore, ALL manic traits are, well, MANIC. They are all manic, but do *not* all occur at a frequency or severity to warrant a label of disorder or disease. Some have taken to calling these "shadow syndromes", which, while perceptively correct, is of limited nosological utility and reveals nothing of etiology. These are, along with the depressive equivalents, the trait expressions of the bipolar personality.
Some consider the "bipolar personality" as too strong a term for directly suggesting the 'bipolar' component. Well, reality isn't always nice, but the truth is only changed for the better when honestly confronted for what it is. To call the truth by a euphemism is an excuse for too many to avoid the necessary adjustments and recalibrations in perspective, diagnosis and treatment. When we all fully understand that these traits are widespread in the gene pool (and have greater incidence in high-stress environments such as north of 55 lattitude, altiplanar, etc., as also certain lifestyles such as severely and consistent discrimination, political instability, etc.) there will be no further stigma attached to these traits, but there will be a healthy respect for them, since many are valuable traits responsible for the majority of great achievements in history.