My theory is that if you need an iron-clad guarantee of privacy, you're not going to get it from a VPN.
If you're interested in hiding from civil snoops (RIAA, MPAA), by all means, use one. If you're interested in hiding from a government, then by all means, keep rolling the honeypot dice.
... in a way that you, as a customer, can detect.
1. You can't have any hard guarantees about what information is retained by third parties about you.
2. As other comments here have pointed out, something smells a bit weird with this.