Everything the show did well:
-The main trio have the best team balance I've seen in Sentai so far, it never feels like one overshadows the other and all 3 feel like protagonists.
-Colon gives great support to the team and is a really likeable character.
-Has a great trio of rivals, the team desiring revenge because of the rivals killing their friends make the stakes in the show feel more personal.
-The villains introduced later are also really likeable and don't disrupt the rivalry between the two trios. Only Butchy and Guildos are initially kinda bad since they come out of nowhere, but by the end they're also really likeable and their sudden appearance is explained.
-The team has an unique fighting style with the way they implement sports into how they fight plus the show having slightly more budget.
-The majority of the monsters of the week manage to be entertaining.
-Really great final arc.
-The plot twist of the main antagonist's true objective is great.

Everything the show did bad:
-The black and green rangers come out of nowhere. Their very existence feels like an asspull considering the plot of one of the earlier episodes and they're introduced so late that they barely manage to be proper characters. Green at least get a few episodes but Black could be removed from the show and the story wouldn't change. They ultimately make the second half of the show feel kinda draggy.
-The majority of the mecha fights feel boring due to being short and the monsters hardly ever retaining their powers once they go giant.
-Too many characters of the week die to take the show seriously. Like they visit graves of dead characters at the end of the episodes too often, definitely more often than any other tokusatsu I've seen. I ultimately would laugh whenever they visited a grave by the second quarter.
-Despite the good choreography, the flow of fights is kinda repetitive. This one is kinda hard to explain but essentially in almost every episode the Liveman lose the same way in the first half. It's one of those thing that one has to watch to understand, just take my word that it isn't like other showa Sentai but still it isn't that big of an issue.
-Personally didn't like Yusuke during the first half of the show. It felt like he was too much of a jerk, which wouldn't be an issue of the rest of the team properly called him out on it. They would acknowledge it but not properly reprimand him. This stops being an issue when Green and Black get introduced weirdly enough but this might be a personal issue.

Reasons for the show strenghts:
Due to Goranger and JAKQ not being acknowledged as super sentai shows, this show served as Sentai's 10th anniversary which resulted in the show getting slightly more budget than usual Sentai seasons and being able to try more unique ideas. Yusuke and Megumi being played by idols resulted in a more different approach in characters compared to other showa shows.

Reasons for the show flaws:
This was main writer Hirohisa Soda's 7th Sentai show in a row. By this point he was struggling at writing interesting premises behind the fights.

Overall:
The show is overall pretty great and I feel it would be an 8 for most people since my problems with the red ranger feel more of a personal thing. The main trio all feel like main protagonists and the rivalry gimmick is really well done. It isn't a super unique show but it's still unique enough. Definitely recommend if you're into tragic heroes.