Congratulations!
At first you may miss some of the things you've grown used to about the 740, such as direct entry of the voice and style numbers. You'll soon find that the new keyboard is far superior in the Operating system, vocal processing, navigation, user memory, and many other aspects.
There are many "tricks" to learning the 2100 and frequent visits to the PSR Tutorial Page: http://psrtutorial.com/
will be a great help.
DonM