I'm only speaking from personal experience and mostly with Typescript for both but CodeWhisperer feels like it has more lag before offering a completion and the completions it offers are often worse. It duplicates lines that already exist, it adds inappropriate indentions, where Copilot very helpfully finishes your line and stops, CodeWhisperer tries to add three more lines entirely and you reject it far more often. It's not worthless in this current stage, but it's not something to strongly praise either.

The security checks and OSS attributions feel very much like what "enterprise" software does when they know they can't compete, they tick boxes instead.