Online store owners of Reddit: What's your take on Stripe vs Paypal vs Square (online credit card processing service)?

Is it wise to use them all or should I just stick with one particular? I know they have different processing fees and pros/cons…etc. One of online store portals I'm looking at only accepts Paypal and Swipe for the payment. But I also see many businesses now days are using Square and it looks like a good option especially for the Point-Of-Sale(?) system —where I can sell my products outside the online store (ex. face to face). What are your takes on those online CC processing services? Any suggestions/advises are welcome! Thank you for your help!