Everything the show did well:
-Really great cast overall from both the heroes and villains side.
-The Roidmudes generals are among the best villains in the franchise.
-Everyone in the hero side is useful, specially this show's main girl Kiriko who is one of, if not the best main girl in the franchise.
-Pretty great action.
-Great final arc.
-Good plot overall.

Everything the show did bad:
-The show has a really slow start, this is mostly due the monsters of the week being amongst the franchise's worst, almost Wizard-tier and doesn't help how easy it's to predict the outcome of the cases if you've seen other tokusatsu. Since the main villains are barely involved in the first quarter aside of Machine Chaser who doesn't have a personality due to plot reasons, these make the beginning feel really draggy. However it's more stomachable due to how likeable the main hero cast is and by the second half they drop the monster of the week aspect.
-Mach/Go drops his lighthearted personality fairly early on and comes of as a jerk during most of the show's middle but at least he manages to be a really likeable character by the end.
-The Sigma Circular fight in the finale feels forced.

Reasons for the show's strengths:
The show's producer Omori is good at coming of with cool motifs and executed the car motif in a very different way from other tokusatsu.
The main writer Riku Sanjo is really great at writing characters and at world-building.
The popularity of Baron from Gaim lead to the creation of Chase but Sanjo and Omori didn't want to repeat concepts of previous shows and managed to make a pretty unique execution of the rival concept and it was done really well.

Reasons for the show's problems:
I honestly am at a complete loss a to what caused the first half's monster of the week so repetitive. Main producer Omori seemingly didn't request this idea in fact it seems that he was the one who requested for the show to become more serialized in the second half. Main writer Riku Sanjou is really great at writing episodic monsters of the week, even when they're 2-parters. Heck, his previous rider show W was good at having mystery-focused monster of the week. I guess he can be inconsistent since he made Ziga which was a pretty mediocre manga but I honestly felt that it could have been an issue of the manga's editor. He also was the main writer of Digimon XROSS which sucked but in that show the problem was that he barely actually wrote in the show and that the show shifted producers 3 times. The problem also cannot be this show having multiple side writers since he wrote most of the episodic stuff, W was made in the same conditions and the most recurring secondary writer was Keiichi Hasegawa who mostly wrote for the second half.
The only reasoning that comes to mind is that he already had a story draft prior to TV Asahi requesting the show to have detectives (which is honestly weird since this is the only time that comes to mind where TV Asahi had a major creative decision in a Toei's Tokusatsu since the early 90s) so he head to impromptuly scrap it resulting in the first arc being more sloppily written but even that feels far-fetched since that seemingly happened way too early in the pre-production to be a real issue.

Overall:
Really great show overall, its start drags it down but not by much and still manages to be a great time overall. Highly recommend to tokusatsu fans or to fans of lighthearted cop dramas.