EDIT: After the changes to his BBs and DCs Some of my opinions don't hold true anymore. Updating it accordingly.

Initially I was going to post a comment over on the post about Zedus' Unit info, then I soon realized that I had typed out a bit of a lengthy message, so I figured I'd make my own post. It's been a long time since I've had any desire to chime in on anything really, but for some reasons I feel like giving my two cents on this guy, at least for anyone who might not be getting it, as personally a lot of his design seems counter intuitive. Please go and look his info before you read, it will make things I am saying a lot clearer! (Special mention to /u/Deathmax for the changes)

Now the 6 star is the one you will be using end game, so let's start off with the leader skill: 125% boost to crit dmg, 40% spark dmg boost, and 15% crit rate buff.

It's rather good, but it's not absolute top damage either. Using Maxwell's full leader skill you are going to be rocking way more damage than that, so it's perhaps redundant (especially giving how he stacks up normally to Maxwell) however assuming that you aren't taking advantage of the elemental weakness, then it does become a flat out better skill, since that 40% spark damage is just flat out more than Maxwell has, and the 15% innate crit chance is nice. Possibly useful when you aren't trying to one hit kill an enemy, or if you are trying to do that for many enemies of different types. By itself the skill could be useful for Frontier Hunter and Raids where there are multiple bosses with different elements.

Alright so with that I would move to his normal hit count, which I can't seem to find, granted it's hardly a big factor. Only thing of particular note would be if he's rocking 30 DC which would make him a rather great arena unit. Not much to say about stats either since I can't seem to find that either (may be blind on my part), but as we all know stats are really more a bonus, DuelSGX is still a viable and rather useful unit, so that's not really the biggest factor unless he's crazy low (or high).

So his normal hit count is sitting at 10, which means he's not really going to be producing much BC at all. Combined with his BB being single target, he's really not going to be any use in arena. He's got good HP at ~6300, good ATK and DEF at 2100, and 1755 REC. Stat wise, he is very decent, and well balanced, no issues here at all.

Now then the BB and SBB. His BB is sitting at a 550 multiplier, not to bad at all, but it's single target so it has limited uses. His SBB has a 600% multiplier on it, which is only 10% less than maxwell. He also has 5% more ATK than Maxwell, and higher Imp caps, so he's definitely a heavy hitter.

100% innate crit chance has been removed from his BB/SBB, this isn't really that big of a lost in all honesty, you're probably going to be a crit cap with him normally anyways.

Anyways back to the BB. 40% spark boost is nice. I am not sure where you would exactly need this, as there are so many better spark buffs, and it's a rather useless buff in arena, so yeah. Wouldn't say it's that big of a deal. Now his SBB on the other hand has 70% spark buff, which is comparable to say Elza, which is still a very strong units. Only a few others have a stronger buff, so it's very respectable.

The last thing to note, is probably his single biggest weakness. 9 DC on his BB and more importantly 3 DC on his SBB. This is terrible, any of you who have used bugged units at 1 DC know that your BBs don't fill well at all, unless you are using leaders which boost BB when sparking, the problem with that is, well, he only has 3 hits. That's not a lot of BC produced. He relies on his allies to produce nearly 50 BC on average with no BC effectiveness lead. That means he's effectively useless for things like Frontier Hunter or at least is not a really big hindrance on your team, which while you may be able to maintain him 100% you'll question why you don't have a Mifune in your team to help fight the RNG of crystal distribution.

His drop checks have been buffed, meaning what was his biggest problem is no longer there. His BB now has 18 DC, not bad, but it's still single target so it's not going to produce all that much BC. His SBB now has 24 DC (up from 3 lol) which is very good. This change makes him completely viable for a lot of things, and even top teir in some.

With the changes on the Drop checks, Zedus now has a very distinct spot he fills. A very respectable Maxwell substitute if you can't get him, a monster Frontier Hunter Leader, and more prominently he works with Maxwell to give you 70% crit chance without any other crit buffers, and an insane damage multiplier, and his still has that spark buff, meaning you now have 4 free slot to grab an attack buff and you can do whatever with the remainder! (Mass Breaker Mifune :P). He's now a very viable and solid pull!

Edit: Spelling/Wording and Fixed info

Edit 2: As /u/Dagonx321 has pointed out, should Zedus at a later time revive a changed drop check his viability and usefulness changes drastically. He becomes a VERY potent duo lead with Maxwell then, hitting crit cap without another leader, freeing you up a unit slot. He still does that currently, but he still faces his massive dropcheck problem which makes him less appealing than Dual Maxwell. I'd say 15 DC would probably be usable, with numbers around 30 bringing him up to ridiculous and OP levels. We'll have to see what Gumi does with it though.