Sparrow does indeed use Samourai's Whirlpool.

Agree completely with DaveF above. Sparrow is the best choice by far. Wasabi use the fees you pay them to actively fund blockchain analysis and pay the company Coinfirm to analyze your UTXOs, spy on your transactions, and decide whether or not you are even allowed to use their coinjoin implementation at all. Add in the fact that they suffer from endemic address reuse (https://bitcointalk.org/index.php?topic=5419000.msg61220171#msg61220171, https://bitcointalk.org/index.php?topic=5286821.msg62085316#msg62085316), and I would steer well clear of ever using Wasabi.

The most important thing with Sparrow is to ensure it is pointed at your own node and connecting to the Whirlpool coordinator via Tor.