NFASTRO, check out Antennas Direct. They come out with new designs all the time. The laws of physics aren't being amended though so there's some constraints on what's possible. Most of re-designs are aimed at optimizing channels 7 to 51, and to attract people to OTA by having aesthetically pleasing products.
I've bought 2 AD products now to replace my old Channel Master. Channel Master just seems to be interested in making the same products cheaper (and not pass on the savings to the customer).
http://www.antennasdirect.com/