Define 'good' and 'positive'. Those words mean different things to different people in different situations.
If I could fund my PayPal account with Bitcoins and pay any other PayPal user in their currency of choice, that would be convenient. If I could receive funds from others through PayPal and withdraw those funds as Bitcoins, that would also be very convenient.
But that's not how the paypal visa works. It is, by all accounts, a regular credit card with a credit limit. You pay it off by transferring funds to your account by a certain date. I'm sure paypal would accept BTC to pay it, but all paypal is going to do is convert to USD to avoid volatility risk. So... what is the point?