So LEDs yeah or neah?

Cree is the brand name of the LEDs and the website is rapidled.com

 

As I understand it Cree is an LED manufacturer. They make the actual diode which then needs to be fixed to a circuit board. The diodes are fixed to circuit boards by resellers such as RapidLED, LEDgroupbuy, StevesLEDs, etc. who sell them to consumers mounted on small circuit boards (referred to as stars). So you can buy Cree LEDs from any number of resellers across the internet.
Myself and many other people here have had a good experience with RapidLED so they are typically the go to guys for DIY LED projects.
Also not all LEDs are created equal. The typical consensus is that Cree is the best for reef tanks though. The hierarchy goes something like: Cree>Phillips Luxeon>>Bridgelux>Generic LED.

Note that this only applies to DIY LED setups as I am not sure what brand of LED AI, Ecotech or anyone else uses.

 

Diy are ok for some. I have all AI and couldn't be happier. Nice looking fixtures and controllers Iowa based company and great Reviews

 

Ais use cree leds not sure about radions. But ai is iowa based and look nice and clean vs alot of bare wire. Good price. Theyll always get my vote. Btw my sps grows like crazy under them.

 

LED all the way. It's not even close.

Rapid is a DIY seller. AI's are pre-made fixtures.