I am one who feels that the best defense is a great offense with my Fallen armor and my Khorovod. Thus, when I seen the Swiftstrike Buckler, I felt that I really needed one. Granted, it won't block a single thing in Tier 3, but if I'm overwhelming just about any enemy with the speed of my strikes, what does it matter?
And so far, I've been really happy with the results. My Khorovod has an Attack Speed Low UV, the Fallen set gives Medium Attack Speed (For both my swords and my gun!), and the Swiftstrike Buckler gives a High attack speed (again, to all weapons). This gives my Khorovod max attack speed while giving "ultra" attack speed to my other weapons.
The only problem with this: Devilites. Since the Fallen set makes me deal drastically less damage to Fiends, and since I can barely block any damage in Tier 3, they are the most problemsome enemy. Which is why I never go alone in Devilite levels. :P
Anyway, I was wanting to know the overall thoughts on this shield? It's probably the one I'll be using for the rest of the game, even though the Barbarous gives way more defense and attack damage. It's hard to beat the High Attack Speed boost.
Oh dude, I totally use a swiftstrike+fallen combo too. Having IAS:Ultra with all weapons is really fun. My weapon set is [Khorovod CTRMed/Callahan/Valiance], DA, GF, and the triple slash trick (http://forums.spiralknights.com/en/node/13083) is super nice with that kind of attack speed.
For a while, it made me feel like my Barb Thorn was a waste of time/money too, since I could just poke in and out so safely - in fact, I really couldn't play without anything higher than IAS:High for a while because I kept trying to move when I was in pure animation lag.
It's really nice when you're soloing, so long as you choose your gates wisely :)