I've used GIK products in the past with great results - outstanding performance vs price. I really like the appearance of the new Impression series but am confused over the difference between those and the Alpha series - is there a performance difference or just different appearance?
The Alpha panel is a true binary sequence so it will give nice amplitude diffusion. The Impression series is a more of a design so it does diffuse/scatter but without the binary sequence. With both units the wood front acts as a membrane, so it helps not only retain the upper energy in the room, but also helps absorb more low end (drum effect from the wood). My first pick would be the Alpha, as I am a SUPER ACOUSTIC GEEK

, but the Impression does a great job for the reasons I listed above. Needless to say I don't think you would go wrong on either, so if you really like the looks of the Impression then I say GO FOR IT!
Glenn Kuras
GIK Acoustics