DISCLAIMER; As with any trails game, I would only suggest playing through this if you have played Cold Steel 1 and 2, as this is a direct sequel to the games prior, and these games are very plot driven. (Note: Sky Trilogy or the untranslated Crossbell duology will also help with understanding certain plot elements/references, but are not strictly necessary)
As another entry into the long running Trails series, this is definitely up there as one of the best in the series as a whole. With nice new additions to the gameplay such as breakbars for extra damage and stuns, as well as Battle Orders for new party wide buffs giving more use to Bravery Points from link attacks, combat is debatably the best it's ever been. As for the plot, it does a great job at providing a new cast of characters, bringing back old ones, while also providing genuinely good fanservice with even older characters and satisfying pay-offs/continuations to plotlines from the other series.
The only real major thing to bring up in regards to criticism is the fact that some elements of the plot that are used are related to two games in the whole Legend of Heroes: Trails series that have not been translated yet, not a dealbreaker, but it certainly will have less impact if you have not played/heard anything about the two games before the start of the Cold Steel sub-series.
TLDR; If you're a fan of the Cold Steel/Trails series, 100% pick this up.