I use them both for different things. I would only use Paypal with ebay for instance as Paypal is great if there's a dispute between the seller or if you get scammed because you'll easily get your money back but that's where it can be abused by criminals. You could easily get scammed using bitcoin though if you didn't use an escro. But bitcoin is great for purchasing services like hosting and proxies or if you wanted to buy stuff from the deepweb you're going to have to use bitcoin  so both have their uses and positives or negatives.