Briefly…
Pros: A wider range of modern codecs and formats; multi cam; key word (data-based) organization flexibility; speed (workflow and processing – optimized for newish Macs); Titling (Motion projects).
Cons: Limited audio editing (compared to STP); limited interoperability with Motion (no Send-to-Motion); very basic tape capture; very basic DVD and BD capability.
Since you use DVDSP for disk authoring, I suggest that if you make the change, maintain a separate bootable volume for DVDSP (and the rest of the suite) on your current OS. Each time a new version of OS X is released, it seems that something in FCS falls by the wayside…
Good luck.
Russ