There are reasons to upgrade it and some points that say not to.
upgrade recommended because.
1.Enhanced session mode:
The ability to use any screen resolution that your connecting machine supports is a very large draw for this new version.
2.Online resize of virtual disks:
Online resize can help split the difference. You can create a disk that starts off initially small and then grow it without downtime. Besides, even people who make an effort to provision properly and use thin provisioned disks can still make errors of underestimation. Online disk resizing also eliminates one of the last reasons people give for pass-through disks.
3.Live migration enhancements: If you’re moving VMs around in production on a regular basis, you either have a very large environment or something isn’t right. So, speedier Live Migrations wasn’t high on my wish list.