I did, but I wanted to point out to the OP the scenario of shared computers, since people often only think about a single user sitting at a single computer. Someone using a shared computer for 5 minutes is likely to be better protected with a session cookie, compared to a persistent cookie (albeit with an expiry time of 20 minutes).
I realise it's not black and white, I am just pointing out a scenario that the OP might not have thought about.
