What about mine? Not so good?

Sorry but you designs were very well done. But it doesn't look like a coin, does it?
Rubbish. Where you want to use this logo? It's obvious that it's new coin. Ripples, MasterCoin, MegaCoin, WorldCoin, DataCoin, DigitalCoin and etc. so many coins doesn't use actual coin look.
Try to resize one of this "logotypes" which you suggest. You will see that it will be trash, like EZCoin logo, JunkCoin logo and etc. Example -
https://dl.dropboxusercontent.com/u/36382809/SSSSSC.png