I think Currently Full Whammy is the only upgrade path. honestly I dont see Platinum as a requirement for anything involving home recording. Full fledged studios sure, but for home demos and recording not so much. I have platinum and I barely use anything in it besides what would be the Metal & More and the standard EX Stuff. Snare 5 kick 10 Quick Toms are my main instruments. Once in a while I will go with the Panty kicks and snare, DT Kit from time to time. But i find Kick 10, Tone Def Kick, Snare 5 Snare 11 and Quick toms to be my GO TO for Metal.
I did use the Nashville kit once as well on a country song I did, but even that is included with EX