RPMs and DEBs are different package management format. Both of them achieving the same thing. Installing software packages automatically.
The VicidialNOW kernel has been modified for optimum Vicidial and Asterisk performance. The default CentOS kernel was lacking in some aspects for optimum Vicidial performance specially when using hardware telephony cards (E1s, TDMs and etc).
Upgrading to future versions of Vicidial is really easy if you follow the UPGRADE.txt document on the Astguiclient zip file. It actually involves less than 5 steps to do it. You just need to learn basic Linux to do it. There is no need to wait for the next version of VicidialNOW.