Royal Decree v Trap Stun
Fiendish Chain v Breakthrough Skill
Stygian Dirge v Mischief Of The Yokai
The first one isn't even comparable. Trap Stun is for decks that need traps (so can't run decree), but want a way to stop the opponent from using them. Decree is for decks that don't need the traps.
Fiendish v.s Breakthrough is more based on how important the fact that it can stop attacks is for your deck. I generally run Breakthrough, unless my deck needs the added defense that Chain offers.
And I much prefer Yokai. Can't be msted, and you can reuse it from grave. And there are a lot more decks that can handle being dropped 1 level (Stuff like wind-ups, constellars, inzektors, etc) that run 2 ranks one right after the other 4-5 or 3-4, so stygian they just use the others. Also notable for rank 4 decks that run guide, as they have the rank 3s to go into now. However a drop of 2 is a lot more notable. plus the second eff only changes 1 monster, so there's not gonna be an xyz you can make.
And personally, I prefer Wiretap>Seven tools, simply because Wiretap can never be a dead card (Like, life points wise). Normally if you're running either of the 2, it's because traps would screw over a big push of yours, or some other play. Meaning it won't matter as much that they can redraw it. If it's something like Bottomless or Warning, you're already set up so if they draw it it won't save them. If it's like d-prison or mirror force, you're probably going for game if you're using your negations on it, meaning they won't get to redraw it

