The color selections offered were well suited in my opinion for the Blackberry Storm I was testing it on, each Blue, Red, and all of the other colors were vibrant and displayed immediately.
I also appreciated the multiple alerts option which I tested by sending myself an SMS and an email one after another. Almost immediately my LED display alternated between the two colors at a fast enough pace to realize that two messages were sent, yet slow enough that I could see what type of messages were waiting for me to reply. It's perfect when you just want to know how many messages are on your phone without checking the phone itself.
I also tested the "rapid LED flashing" option which I actually found to be less impressive, it basically allows the LED to flash when incoming calls are sent. While its cool to show off the LED, its rather pointless since I can feel my phone calls vibrations and hear the ringer. Sure I can see a call is coming in without sound, but a rapid LED wasn't necessary. It might be a good feature if you leave your phone across the room.
I also loved the ability to customize the timeframe in which the LED would display, with typical Blackberry devices you have 15 seconds of alert time, with Berry Buzz I could set an option that would keep the LED lit until I acknowledged the message. If you want to make sure you see the message at a later time its easy to simply not acknowledge the message on the device and grab it later.
Finally I appreciated the battery saving measures offered by Berry Buzz, specifically the ability to slow down the LED flash to conserve battery life. Overall I don't see the battery issue as a big issue but its still nice that its been added.