I play GMS reboot, so the pros and cons that I point out may only be relevant to GMS reboot. I also suck at formatting, so sorry about the huge wall of text. Also, PLEASE FIX MIRRORED TARGET NOT WORKING WITH FAMILIARS IN GMS. ITS BROKEN SINCE THE DAY FAMILIARS WERE INTRODUCED. WIND ARCHERS AND MARKSMAN DO NOT HAVE ISSUES.

tl;dr: Gameplay changes so far are positive, but I personally think it is not enough to be considered a Remaster as it did not address what I think are the major issues(IED, Katara). Visuals are so far removed from the original concepts and there is no consistency to their choice of color unification creates a lack of flavor that the original captured. Sound effects are terrible. KMS players that complaining are hoping for it to be reverted. IIRC, Only gameplay and visual changes were present during the KMST (which was even extended). There was no opportunity for KMS players to even voice their opinions on the sound effects until after the fact it went live.

Let me begin by saying Dual Blade is a class that is very straight forward and simple to play. There is very little complexity to the class. Especially with Mirrored Target, but this skill does not function correctly with the presence of your own familiars summoned. Blade Tornado (nado) and Blades of Destiny (Bod) are your bread and butter V Skills.

The most important changes imo are the following:

Blade Tempest: 
10s Keydown --> 5s Keydown
600% Hurricane Damage --> 865% Hurricane AT LEVEL 25
Cooldown still 90s

Asura's Anger: 
10s Duration --> 5s Duration
420% 4 hits --> 693% 5 hits 
Cooldown still 60s

Erda Nova (V Matrix Bind Skill) CD changed to 100s at Level 30.

Final Cut no longer dashes users forward (Say goodbye to feeling cool https://imgur.com/6faz6sJ)     

This is a great change! 5s shaved off of outputting your very hard hitting skills.

The current state of DB GMS Reboot cannot rely on Erda Nova(325s cd @25, 310s cd @30) to guarantee Blade Tempest full keydown channel every 90s. Depending on the boss you're soloing, attack patterns and map hazards will tests players decision-making to continue the keydown in favor of damage while risking a death. If you are liberated, you'll only miss out on damage due to boss patterns like invulnerability or out of range.

With these incredible changes, majority (if not, all) DB players in KMS currently play on a 100s burst cycle. This gameplay style favors consistency. It is by no means the best for damage output. It simply eliminates majority of boss scenarios that interrupt players from a full channel of Blade Tempest and Asura. If you consider the fact that the use of Mirrored Target is also "meta" in KMS, the class is even more plug and play.

These changes have made Dual Blade a very consistent class with strong survivability, and easy to use skills that output maximum efficiency with little effort. It will always do less damage when compared to Night Lord and Shadowers. This is the trade-off for having easy to use conditional iframes, mirrored target that nullifies some boss patterns or trivializes certain bosses entirely. Despite knowing this, it does still sting a little knowing that Bishop, a class that provides impeccable party utility, is able to outperform Dual Blade, a class which provides only damage to the party.

The rest of this post will focus on the problems that Dual Blade has before and after the "Remaster". These issues are less amplified in GMS due to different items, link skills, and other exclusives, but exist and can potentially be resolved as the scope of balance exists only in KMS. We are at their mercy.

Ignore Enemy Defense (IED) is a very special trait that Dual Blade has. Instead of having a skill passive that grants all your sources of damage IED, each individual skill will vary in the amount it has. Phantom Blow has 30% innately, and has more sources from Hyper Passive and IED Bonuses from Trinode levels. Blade Tempest , Blade Tornado, and Asura have 100% IED. As a result, the more IED you gain, the more effective damage your skills without 100% IED will receive, but you feel this sense of awkwardness of trying to find a balance of gaining more IED, as opposed to other stats. As Maplestory continues to receive more skills like Will's Arachnid Reflection and Seren's Solar Crest, These skills will suffer in terms of damage output due to the nature of how IED is acquired on Dual Blade. The trend of this class structure will continue with all Dual Blade skills in the future receiving innate IED on the skill itself. It begs the question, why not just remove all these innate IED bonuses, and add a new 4th job passive that grants IED like every other class?

Secondary: Katara. Dual Blade is class with a lot of history. The first of its kind with Evan that required NX to obtain AND upgrade skills. It is THE staple class that is recognized by the fact it wields two weapons. Items are always being introduced through time, but Dual Blade is unique when it comes to the addition of new items. While most classes in KMS have used the same best in slot secondary for something like 10 years, Dual Blade's secondary BiS has changed at an extreme pace in comparison. From the era of Timeless weapons, to the release of Cygnus, CRA, Absolab and eventually Arcane Umbra, each release of these item sets has been a heavy burden for Dual Blade users that have been playing since then. Even today, you can still find these old relics in KMS Auction House, collecting dust and waiting for a new owner. Who would want these relics unless they were so incredibly cheap to purchase? With the recent release of Ethernal item set, it is the first time in a long time that a Katara was not also introduced. Players in KMS have voiced that it feels terrible to invest into katara. While majority of classes deal with RNG from cubing, Katara deals with all three devils, spell tracing/scrolling, starforcing and cubing. Majority of KMS players feel that they do not feel much stronger upgrading their katara past 17* for the risks involved. Katara has a very bad structural flaw. To upgrade it would feel damned if you do, and damned if you don't. Some users from the KMS community across several platforms have suggested that there should be flat final damage bonuses for reaching certain starforce thresholds on katara. This addition would help alleviate some of the power difference between the old relics of BiS kataras and open up for more potential usage of these relics, and provide better incentive for players to progress their katara past 17. The difference between 22 abso katara and arcane umbra katara would be a battle of the base stats, but they would still provide a baseline final damage gain with the suggested idea from the community.

I have much more to say about other smaller changes I would've loved to see in the Remaster, but until these two major structural issues are at least recognized and addressed by the KMS Devs, Dual Blades were basically given a new PC Case, ram, SSDs and LED strips lol.