Foowloing are the changes in cent os 7 :-
- New initialization system, systemd.
- New firewall control, firewalld. This adds a more dynamic and flexible way to control the firewall module in the kernel, which is still netfilter.
- New bootloader. GRUB2 adds rich scripting support as well as support for the new hardware options offered on modern mainboards.
- New default filesystem, XFS. XFS adds support for larger single filesystems, faster format times (0 seconds), integrated snapshots, and live filesystem dumps for backup without first unmounting.
- GNOME 3 – This only really applies to those who use RHEL/CentOS in the desktop, like me. As with any other distro, you aren’t locked into GNOME 3. I personally like it, but KDE is readily available and others can be found on EPEL.
- If you are used to previous versions you may want to stick with 6. 7 has a lot of command changes
And in our env we are using Cent OS 7. Still Didn't face issue with performance etc..