take a quick look: http://forums.spiralknights.com/es/node/33594
Corect me if I'm wrong, but the only monsters that seems not to deal normal are wolvers.
This kind of makes these sets less appealing since they are too specific, while everything else is more forgiving if you get hit.

With the advent of arsenal stations, I don't think the popular skolver + divine veil is anywhere near as useful as it once was. (And, there are people who argued that it was never good, but let's ignore that part.)

It used to be that you could have things like poison themed stratum where you could easily face all types of damage when going through it. Now, however, you can switch on each floor. It is very rare to have a floor that has a lot of shadow *and* a lot of piercing, so having several 4* armors that you can switch around to match your floor is going to be more effective than having just the two 5* skolver + divine veil.

Arsenal stations make a bigger impact on your weapons. While a lot of armor has significant changes from 4* to 5* (doubling bonuses, changes from normal/piercing to normal/elemental, etc.), the difference between the weapons is usually much more minor. For example, a weapon that causes fire isn't very useful on a floor with a fire theme, etc. A fire themed stratum might have fire constructs on one floor and fire wolvers on another, but now you don't need to take two different weapons.

In general, it is now much more useful to have many situational 4* items, and fewer weapon slots. Of course, if you can afford it, having lots of 5* items and all 4 weapon slots is still better, you just don't need to go to 5* stuff right away.

As far as the original three types of armor that the OP mentioned, they are now mostly worthless.

I use a combo set when I'm jumping into random parties or going danger room hunting. My personal one is Silvermail plus Miracle Hood (gonna up to Radiant and Grey Feather eventually) and an Ancient Plate shield. Got my Voltedge, Silent Nightblade, Gigawatt and Dark Thorn Blade for weapons. I can take on pretty much anything.

But yeah, normal damage is still way too common in T3 to completely give it up.

I tend to avoid the going with pure dual special armors because almost everything in this game deals split normal damage. So, equipping a pure set of dual special armor leaves you vulnerable to almost everything in the game.

However, mixing dual special armors with other armors may provide you with a good all around defense. The problem is that the arsenal stations came out, and most levels deal one type of damage only. So, the only time you would want to use the dual special armors is when you run FSC, when your friends keep inviting you to random strata, when you don't want to bother with constantly changing your armor, and/or when you want a challenge.