Long story short, the major difference is the Tx0. With Wasabi if you are mixing 10 BTC, I can trivially track that 10 BTC as it is peeled down into smaller utxos. The left over change is part of the mix tx, and thus creates a determinstic link that follows it until completion. You literally leave crumbs along the trail. With Whirlpool you mix 10 BTC and the fee and utxo creation is handled in tx0. After tx0, upon first premix, all certainty is lost, there is no crumbs, there are no deterministic links, there is just the theoretical perfect transaction, for every utxo associated with tx0. So Wasabi, long peeling chain. Whirlpool no peeling chain, after tx0 you cannot with any certainty connect a single input to a single output.