The new architecture is orders of magnitude cheaper and more performant because it's leverage Arweave/Bundlr rather than broadcasting every tx to Polygon directly. Benefit is they inherity the strong CR + DA guarantees of Arweave/Bundlr, while reducing costs + latency.
The big difference here is that if user's want the composability of EVM (e.g., having posts be NFTs) they can, but it's optional -- not the default. That's a step in the right direction