Everything the show did well:
-Likeable cast for both heroes and villains.
-Dyna Black in particular is a really likeable character and also has an extremely cool fighting style.
-The direction in this show feels like the natural evolution of the directing style of the original Kamen Rider show. Looks consistently great from beginning to end.
-The show is pretty funny consistently.
-The overly ridiculous premise mixed with the usual Showa darkness makes for a pretty fun experience.
-Fun monsters of the week.
-Prince Megiddo's arc is really great.
-The cast interactions with the science center are entertaining.
-A sizeable amount of out of suit action, more than an usual toku show.
-First Sentai show to use wire action and it was used really well.

Everything the show did bad:
-With the exception of the black ranger Ryu, the other 4 rangers while likeable feel pretty generic.
-Dark Knight's fighting style kinda sucks.
-While Emperor Aton manages to do a lot of cool stuff in the final arc, he's still mostly a 'sit in the chair doing nothing' type villain, and prior to said final arc he didn't have much personality.
-Aside from Megiddo and Zenobia, the other villains are kind of generic.
-The premise isn't that unique.

Reasons for the show's strengths:
Despite the show's runtime being shortened half-way through and the team being changed from a baseball-themed into a science/dynamite-themed team fairly late into pre-production, the show's team did a fantastic job and didn't really let any of this issues affect them significantly. Producer Takeyuki Suzuki attempting to make the show more anime-esque due to his experience working in the medium worked in the show's favor.
Dynablack's actor Junichi Haruta being an ex-suit actor allowed for way more out of suit fights than usual and for said character do to of cool stuff.
This was Hirohisa Soda's second Sentai show, so they hasn't started to overlap yet.

Reasons for the show's problems:
At the time Toei listened to sponsors more than they do now so that made their shows feel troppier than they do now. But honestly Toei was great at doing ton of fun stuff despite this, Amazon, Skyrider and Black RX are the only shows that were really affected that come to mind. But I assume this is the likeliest factor for the show not being that unique.

Overall:
While it doesn't have a story that original, the show has ton of polish for the time and its monsters brong ton of life to the show. If you don't mind the show going on a pretty safe direction, this is a great time.