I flashed this as my first rom. Followed the how-to videos at XDA exactly. I'm quite happy with it. I got sick of waiting for AT&T & Samsung. I've been reading these forums every day hoping for signs of 2.2, and what do we have? Still absolutely no word on anything official from them. I was more comfortable with the cognition release because it was based on the Canadian Captivate.
The music search bug with the Samsung player is now totally fixed, you can copy text in gmail messages, google maps 5.0 works tons better and you can rotate it. And because of the voodoo lagfix included, there isn't this lag problem for me anymore.
Also the 2.2 clock app seems better because now there is automatic daylight savings time adjustments for the world clock (before you had to somehow know when a country went on or off).