If everything is working fine then there is no need to change. Usually people would change if their network releases a new modem as it's better to be on the recommended modem used in the original firmware by your specific network or if people are having signal issues. All models work regardless of rom. I've flashed many modems and all have worked fine find the right one and stick to it.
Sent from my Nexus 7 using Tapatalk
Phone: Samsung Galaxy S4 I9505
Rom: AOSP GE 4.4.2 by Danvdh - Fast! | Der Kernel: KT Kernel
Tablet: Nexus 7 2013 32GB
Rom: OmniRom 4.4.2 | Der Kernel: Stock Omni
Previous: HTC DesireHD > Samsung Galaxy SII > T-Mobile Rapport > Samsung Galaxy S (Backup) > Samsung Galaxy SIII (Brief ownership) > Samsung Galaxy Note II > HTC One X > Nexus 4