i'm very much lacking hard numbers, but i noticed something similar with jet boots' PAs seeming underwhelming. this seems to be a theme for tech weapons, of course—the low photon cost and quick execution time might balance it out to some degree, but i'm not sure. of course, having a gap-closer in spinning gust helps a lot. jet boots also have jetsweep jolt to boost their overall dps and add some flavour to rotations. i've been doing gust→gale to charge it up quickly and then using it off cooldown to decent effect (and taking time to trigger barta blots, etc.).
presuming the whole jet boots kit is worth using, i feel it's got one of the most enjoyable rotations of any single weapon so far.
regarding the weapon action counter, it does a lot more damage than the jet boots step counter (something like 25-50% more damage?) but also seems to take longer, which fits with other weapon action counters like sword. the weapon action counter also works similar to twin daggers' in that the second attack will chase enemies vertically. it has very good travel distance, so i'd recommend getting it to augment your overall mobility. thrust drive could probably perform the same role, though! i personally also like having a weapon action counter because it can be used against airborne enemies or ones with tall hitboxes.
soaring blades' PAs feel good and have pretty nice cancel freedom with the step dodge. the step dodge seems to do decent damage—comparable to the jet boots' weapon action counter, though slightly less. they're also pretty versatile. the gap closer, roaring pheasant, acts a little strangely in that it "loads" damage during the first part: if it contacts an enemy at any point during the charge, it seems like all the previous hits that missed will strike the enemy at once. this means it's worth using at range despite how slow it is to close distance.
regarding the duration of the PAs, i'm pretty used to long ones thanks to playing partisan a lot, but it seems like there's a decent amount of flexibility there as well, since you can choose exactly when to "convert" an attack into its alternate form. destructive stork (what a name!) can be converted instantly to fill a small damage window fairly easily; rampaging harrier can be converted to effectively "cancel" it at any point with a decent burst of damage; and roaring pheasant can be used at range and converted near the end to maximise the amount of damage you get out of it.
there are two gripes i have, i suppose. soaring blades' weapon action doesn't seem to tie into the rest of its kit very much—it's only used for ranged DPS when you have fanatic blade up (and fanatic blade only affects the weapon action, as far as i know). otherwise, there's basically no point in using it, since it only adds a measly 5% pp gain to normals on enemies that have been hit by the projectiles.
the other issue is with multiweaponing, so it's a bit more subjective. as you've noted soaring blades' PAs are very cancellable, but they con only be cancelled with a step dodge. this makes it awkward to remain in the air with soaring blades, and trying to work in weapon action counters from e.g. jet boots makes the PAs feel a lot more awkward, since you cannot use those weapon actions to cancel out of them. in addition, to work fully, jet boots' weapon action counter requires you to bind their corresponding normal attack, which would be fine except that jet boots have a much worse step counter—you're basically giving up a good step counter for a working weapon action counter. in all other respects jet boots and soaring blades work pretty well as a multiweapon, though—the various features of jet boots are especially beneficial to a soaring blades-focused setup, while the reverse is perhaps less true.
edit: i should have mentioned--i just remembered that i'm still converting my augments to a balanced hybrid setup. right now my results are skewed by me having slightly higher melee damage.