I've never seen Ryukendo before and I took a look at this series because I thought the premises was interesting. Also because a bunch of my friends were watching it, and I'm a sheep. But overall, I was very impressed with the following aspects:
1. The OP rocks! Very catchy.
2. I took an instant liking to Hikaru as he was introduced. Reminds me a bit of Ban, if you turned down the hyperness a few times. However, when he's confused, I see shades of Tetsu. Kyosuke, I didn't really get a feel for in this episode, except that he's pretty laid-back. I like how Rei's a martial-arts girl, and she says that sooner or later, they'll need to know how to fight. Juri, I liked from the start - I just thought she was adorable and sweet. I'm drawn to that type of character. The villians, meh, they're not that great in my opinion so far.
3. Their transformation sequence was very different then what I was expecting from Sentai and PR. The sequence itself reminds me a little of Cruger's from SPD, with them being in a tube of some kind. But I thought it was cool, and I love their uniforms.
4. The ending sequence is also very cute.
So overall, I enjoyed the first episode. I'll be looking forward to seeing more