The myth of transaction speed relating to confirmations and block time...

[thekidcoin]

In the real world, with custom software that knows how to watch for double spends, and instantly realizes that a transaction has been send to the address (take Coinbase for instance - which will be a major player in the USA at least).

For example, I send BTC to Coinbase, and I can trade it within seconds.  If I somehow double spent and the transaction was invalid, there is a holding period for withdrawal's, and my withdrawn funds would be reversed.  Same for online transactions.

With low sub <= minute block times and confirmations, attacks that compromise the blockchain are easily accomplished (AKA pwned).  When this is made public with proof, because it has already been done, good luck with that.  Ever wonder why Bitcoin or Litecoin developers didn't use low block times?  Were they idiots?  No, they knew the dangers.

So to summarize, good luck, and don't invest too much in pie in the sky coins..

[e521]

What if your transaction goes to an exchange and you convert it to another coin influencing the price.
Think about thousands of transactions.
So yes, I believe in the myth.