Since almost everyone I see doesn't understand the economic implications of stake reward, let me explain it for you:

Looking at proof of stake in a vacuum, the stake reward creates decentralized inflation, meaning if everyone stakes, you stay at equilibrium.  What PoS is in a nutshell, is a tax on people who don't stake to support the network.  Everyone who does stake is unaffected, anyone that doesn't stake is punished.  It's not a comparable process to Bernanke throwing money out of a helicopter or anything like that.

Now that the implications of proof of stake in a vacuum are defined, you have to examine it's effects when placed in the real world.  Some people argue for a large stake reward, but if the coin is to actually be used as a currency, it's extremely inconvenient for vendors to have to deal with a monetary supply that has enormous percent changes each year.  If you used a number like 10%, well, the vendor now has to alter his prices by a large amount on a constant basis. 

When you consider the percent of coins destroyed through transaction fees (probably around 1%), and the amount of coins that people will lose per year through accident or death (conservative 1% low ball figure), a stake reward of 2-5% can mostly be ignored by vendors without having to alter prices on a constant basis due to the money supply.  This coin in particular chose a "magic number" right in the middle of what I consider the safe zone, where 2% is a little low, and 5% is a little high.