If possible I would choose bitcoin over paypal for online purchases, but the major issue is not many online websites at a moment accepts bitcoin as a mode of payment and that is the reason paypal is more popular.
That's the problem. I never found a real life shop accepting btc but even the online shops don't all accept btc. It's a rare thing to find something you need to be bought in btc!
It's because BTC is still being "accepted" and not yet mainstream because of slow but steady growth...
It is still being used by many big firms like Overstock, Dell, Microsoft (X-box), and many others...
Also, many hosting firms are now accepting it...
I am just waiting when firms who provide daily used products, start allowing Bitcoins, PayPal will get destroyed...
I think PayPal will itself start using Bitcoins soon if what they mean new money is BTC itself...