This thread should probably be moved to the equipment forum where it would be better answered.
I am not an expert on protein skimmers. A needlewheel is the design of the impeller in the pump that is used to mix the air and water, a better needle wheel design allows for smaller microbubbles, which yields a better foam production for the skimmer.
The pump is something that makes the BK different, Red Dragon pumps are used and if you look at the prices of the RD pumps they are close to $1000 depending on the model by themselves. They are extremely nice pumps, no noise is audible and our RD pump for our BK300I only pulls a small 58 watts. Where our Eheim 1262 return pumps which do not move nearly as much water are considered very energy efficient pull 80 watts a piece.
When we ordered our BK we had never seen on in person. When you do see on in person you will be amazed, the quality and workmanship is second to none I have seen. Once you get it hooked up and dialed in you will also be amazed.
Hope this helps a little,