The tweeters have trickled down from the Professional line, a variant that I had in my ARC ACS265 components back then...boy they are pretty f'n nice. It looks they've incorporated a wave guide in there and used a solid casing. Dome was a 20mm to now a 25mm.
The mid I havent heard, but its newly built from the ground up- new solid basket, copper in the motor,huge venting, that Rainbow treated fiber cone thats used in the profi line...it cant be anything but an improvement all around...and practically the same SLC price point- gotta love that, more for your money. Rainbow maintains good R&D practices and trickles down value over time from their higher end lines.
Cheers.