As with most security, it always depends on what you're trying to defend against. A commercial VPN, even a very good one is probably not good protection if you

As with most security, it always depends on what you're trying to defend against. A commercial VPN, even a very good one is probably not good protection if you're being directly targeted by the NSA. It's very good against your ISP selling your browsing habits to advertisers. There's a spectrum between the two and it's likely decent protection for most of that.