Over the past year... there have been a LOT of new features added to the system. So many... that the "addendum" to the HR20/21 manual would be just as big as the original manual itself. I am amazed at posts from people that find features... thinking they are new... that have been there for a long time. So what features in the system are your hidden "GEMS".... For me: -) Mark & Delete -) Date & Time Jump These two features of the system.... I use constantly..... What are yours?