What would you do?

a. Double the block size

b. Reduce the block rate to a half (average 5 minute blocks)

Suppose this is a one time hard fork. There no drastic technical problems with any of them: "SPV" mining and the relay network has shown that block propagation is not an issue for such as small change. Mining centralization won't radically change for a 2x adjustment.

So what would be best for Bitcoin?

I suspect some (if not most of you) would choose b. Because reducing the block interval saves us real time. Waiting 30 minutes for a 3-block confirmation is... such a long time! Time that we value. Time that sometimes we waste waiting. Time that makes a difference for us. Doubling the block size does not change the user perception of Bitcoin in any way.

Then why most discussions go around doubling the block size?

Each change require less than 20 lines of code (*) in the reference code, and minimum change in other wallets.

Currently there is no idle mining hardware for hire, so the security of six 10-minute block confirmation is equivalent to the security of six 5-minute block confirmations, as described in Satoshi's paper (if there were 51% spare mining hardware for hire, then obviously hiring that hardware for 30 minutes would cost less than hiring it for 1 hour).

Why we discuss a 2x block size increase and not a 1/2 block interval reduction? Aren't we Bitcoin users after all?

Best regards,

Sergio.

(*) b requires increasing the transaction version number, to support the old nLockTime rate.