I replaced a 4 year old similar lock system with this update.  I found it quite easy to install, but did not realize that the lock would not fully work until the entire installation is complete.  This took some extra time to figure out.  In the end it all works well and is an improvement to,prior model.  I also like the design better.  However, the keys, however, are too dark to see easily in poor lighting until you discover that touching the lock button turns on the back light.