5.0 definition is upgraded and high tech than 4.8.
example: if VD of 4.8 detects threats because the threats is executed in your system so you got 2 alerts
1 in the files that is executed and
2 is in a system file, host or you called it a mechanism of executed file
that makes you think you are in multi-attack
in 5.0 there is a file system shield, this system block the infection so you got only 1 alert that make you think 4.8 is better than 5.0.
Regards!!!