I really love some of Decade but at the same time, they NEVER shook the idea I got mid way through that the show rather then being made as a legit tribute wasn't just a short and quickly made KR series on the cheap.
A lot of the earlier stories with the nine worlds were excellent, it is only when there appears to be a creative shift that things started to falter and by the end of series flop.
Pros:
-Story arcs from worlds of Kuuga, Agito, Faiz, RX/Black, Nega Riders and Hibiki are great. Could have easily been stand alone series or movies after it.
-The Rider War Dream opening
-Decade's design by itself grows on you.
-Natsumi-kan!!!
Cons:
-Weak side characters. Mostly looking at Yuusuke and Kaito.
-Dead end plot points/character arcs. The old man as Dr. Shishigami, Kaito being a Rider and knowing jack squat about Tsukasa, Tsukasa's back story in All Riders vs. Dai-Shocker, etc.
-Ugly and uninspired "Complete Form."
-Special effect failures. Kivarra on a string, weak Complete form finishers, pathetic redesign on certain monsters or original ones for the show and the big fights really turned to crap at the end of the series.
Overall, I like Decade a lot, at the same time, I think if it wasn't a fanservice heavy product and just a stand alone, it would be absolute trash.