These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
Narm Charm: It was already pretty trashy when it first aired, and still one can love every minute of it.
Parent Service: There's really no other reason for Deirdre's outfits. See the Stripperiffic entry in the main page.
Special Effects Failure: Every. Single. Monster. Then again this is aping the Power Rangers concept and you know how silly their villains can look.
Visual Effects of Awesome: On the other hand CGI aside all other effects like the sets, the costumes, the battle scenes, and especially knights' armor looked very good considering it was a Saban-Production.
It's a complete coincidence, but Power Rangers Samurai has the same five elements, fire (red), water (blue), forest (green), earth (yellow) and air (pink). Forest and Air were Wood and Heaven in Samurai Sentai Shinkenger, so it certainly wasn't intended to match Mystic Knights, it just did.
Forest and Wood are the same, it's just that Wood has Double Entendre jokes in the West. Heaven was meant as Air. The two are the same because Wood isn't exactly an uncommon Element Number Five.