Interestingly enough here's your answer: http://log.bitcoin-assets.com/?date=27-05-2015#1146160
Worth quoting because I agree with his monetary view. However, I think he is wrong with respect to a proof-of-work cryptocurrency which is not only a financial system but also a device that has the function in a certain way including mining incentives. For the later, a positive rate of inflation is superior.
Fiat money has more or less fixed inflation which is done by the European Central Bank inflation targetting.
No it isn't fixed. It is subject to change at their discretion, which is generally done to favor one particular interest group over another.
A preprogrammed rate of inflation doesn't really differ from a fixed supply, as MP explained, as long as the schedule is fully known to everyone in advance. If we enter into a contract where you agree to pay me 100 units next year, if we both know the inflation rate will be 2% we can instead agree on 102 units instead, which represents the same constant value.
The problem comes in when we agree on 102 based on an expectation of 2% and then the ECB decides that 3% or 1% is better. Then they are favoring either you or me in our contract.
Take Bitcoin, which is non-inflationary by design. One bitcoin is equal to 1/21m of the total. As long as we know what the total is going to be, we can simply agree to transact in units of 1/21m of the total instead of transacting in 1 BTC. There is no real difference. With fiat, you can't even do that, really, because the total money supply is not only not fixed or on a fixed schedule, but isn't even transparent. The best we can do are estimates made after the fact and then often revised.
It made more of a difference when adjusting prices was difficult (required changing product packaging, price stickers, etc.). But in the electronic age that doesn't apply any more.