I admit, I've only just started watching, and I'm only 6 episodes in, but thus far it's looking promising.
The intro, while being very similar to MMPR, is still pretty bombastic and awesome, and this being the 20th anniversary season, it all seems to be gearing up to being a sort of tribute to Power Rangers past, with all the other little references (Like Gosei being an apprentice of Zordon, for instance).
The stories so far have been pretty decent, with no glaringly goofy or silly episodes. This season seems blissfully devoid of comic-relief villains or side-characters (Except for the teacher, but he's hardly in it!)
The fights have been solid choreography. Nothing hugely impressive, but I'm guessing they're saving that for future episodes. Episode 5 had some nice in-sync shooting bits with Yellow and Pink, so that was cool.
The acting isn't the greatest, but it's not the worst either. Most of the rangers are decent enough, and seem to be improving. However Troy, the Red Ranger, is easily the worst. He's good-looking and good in a fight, but he is wooden beyond compare! It's not eve enjoyably bad acting like Divatox or something, it's just flat and dull. Here's hoping he improves. But otherwise the acting is decent enough. It's no Time Force, but it's not as bad as Samurai.
The villains are cool enough, if a little simplistic. Another taking-over-the-earth group, though the insect designs are pretty cool, the voices are good, and Zordon be praised, there aren't any comic-relief villains!
The morphers are a cool idea. I always like unusual morphers that pop open or flip or something, and these are especially odd. The card thing is an interesting concept, similar to Kamen Rider Dedade's henshin-belt in its use of cards, and combining them or weapon combos and such.
And of course, there are all the hints of them using the footage from the Super Sentai movie, Great Hero Battle. H Undreds
of rangers battling hundreds of mooks and monsters? Yeah, cannot wait for that!
So, a bit of a shaky start, but it looks promising. I'll keep an eye on this one.