Hey Edi,
your English is great compared to my knowledge of any other language so don't feel you have to excuse yourself.
As to your question...I don't want to start a mac v PC debate, but....from my own findings....I was always a PC user, thought everyone that used a mac must be a rich idiot. During a festival (Creamfields) I noticed every act that used a computer, used a mac laptop. At the time I was having crashing and random distortion issues and had to buy a laptop anyway so bought a MacBook pro. based on my experience of making music with a computer I can say...
mac crashes less when making music
mac hardly ever locks up, an application may crash and restart (rarely) but my laptop has only locked up once in 4 years
audio handling is generally better with a mac. You can share an audio device with multiple applications, something most sound interfaces do not allow on a PC
If you have multiple sound interfaces you can create an aggregate device on a mac so that applications that only support one interface can drive multiple.
midi over the network or virtual in the machine is standard in a mac, you need a third party application in windows.
mac laptop can run on batteries for longer than PC equivalent (doesn't apply to mac mini)
Generally if you have an iphone or ipad, there is better integration between the mac and ios devices compared to a pc and ios devices
Mac is built on UNIX and has better security by design although Windows is improving with each iteration.
Downside of a mac. More expensive, not everything that's available for a PC is supported on a mac (sonar and some plugins). Battery has to be replaced in a mac store (think this is still true but not sure for latest version- obviously not applicable to a mac mini).
Latest mac machines do not have firewire which might mean extra expense buying a thunderbolt to firewire converter or new interface if you already have a firewire interface.
Just a quick suggestion on the use of a mac mini... if you are interested in performing live, you can configure the mac mini to load up your DAW with a project on boot up. Hook it up to an interface and ableton push or other controller. throw in an ipad acting as a virtual screen and you can perform live without appearing to have a laptop on stage and it all fits in a very small space. You might not need the ipad if you are comfortable without watching the screen depending on your set.