Whoop is an all-in-one fitness and recovery device, while Oura is best used just for sleep.
Oura Ring: https://ouraring.com/product/heritage...
Whoop Strap: https://join.whoop.com/CEFE67

Blog Post: https://powermoves.blog/comparisons/w...

Summary:
The Whoop Strap and Oura Ring are the most advanced sleep trackers on the market.

Their secret sauce is that they track and compare your heart rate variability, resting heart rate, and respiratory rate metrics to your baseline to determine how well your body is recovering.

My conclusion?

If you’re struggling to get good sleep or want to improve your overall health, these devices will help you determine which variables in your life are hurting your sleep. But due to the high price, it's hard to rationalize either device for those who already know their body well.

Oura Ring
Oura is the most comfortable wearable device I've ever tried for sleep tracking. You won't notice it once you get used to it.

It's meant to be worn all day, but its activity tracking is poor because it doesn’t use heart rate to determine calories burned and gets in the way during certain workouts.

Fortunately, there’s no advantage to wearing Oura all day if you have a secondary device to track activity. Your activity data from Apple Watch can be imported into the Oura app to give it a better idea of your activity.
Oura calculates your "readiness score" each day. Oura's score seemed to match how I felt more often than Whoop's score because of Oura's accurate sleep cycles and smarter HRV calculation.

Oura Ring is $300, which is more expensive than basic sleep trackers (Fitbit or Amazon Halo) but a bargain compared to Whoop.

Whoop Strap
Whoop is an all-in-one fitness tracker that specializes in optimizing your recovery.

Whoop excels with recovery, but its data (deep sleep tracking, HRV, and average heart rate during specific exercises) is not accurate enough. If you want just one wearable to track your life, Apple Watch is still your best bet.

Whoop's best feature is the daily questionnaire. You choose which questions you want to be asked, then answer yes or no to the questions each morning. The questions are based on variables and inputs from the previous day (caffeine, alcohol, marijuana, screen time, etc.)

You can get used to wearing Whoop, but Apple Watch is more comfortable.

Whoop is $576 if you plan to keep it for two years. It would be hard to rationalize Whoop's price even if it had perfect data.
You can combine Oura Ring with Apple Watch SE for less than Whoop.

0:00 Intro
0:36 Design: Oura
2:53 Design: Whoop
3:53 Sleep & Recovery: Oura
5:41 Sleep & Recovery: Whoop
8:16 Activity Tracking: Oura
9:54 Activity Tracking: Whoop
11:08 Price: Oura
11:38 Price: Whoop
11:58 Which is best for you?
13:23 The one I’m keeping