Norton Internet Security recommending Disk Optimisation

I have just upgraded to Windows 10 and re-installed NIS (22.5.2.15) and loaded Symantec System Restore 2013 R2 (in lieu of the non-working Ghost 15).     NIS is recommending Disk optimisation for better performance.  If I recall correctly, the last time I tried to optimise my disk it totally messed up the Ghost backups.    

Has anyone any experience of optimising the disk to improve performance and is it worth it?    Thanks

Derek