Dominik is a lovely name and I think there is nothing wrong with the unusual spelling , in fact girls keep telling my DS his name attracts them, makes him different, they are intrigued and it's a good conversation starter.
To be honest girls would be flocking anyway, as I have to say my son is objectively ( honest!) totally gorgeous
, looks and character. He is really popular at his school with his peers as well as the teachers , so he is a good ambassador of his name. I'm sure all who got to know him will only ever have positive thoughts about the name.
He is 16 and all his life had only compliments about his name.
I do have Polish roots hence the name choice. I considered the regular english spelling but since there has always been a possibility of us relocating to Poland I decided against it, as Dominic would be really odd in Poland, in fact it spells ' dom i nic' which in Polish translates as 'house and nothing' 
And I always wanted to call my future son Dominik as this was the name of my lovely best ever cousin who emigrated to the States when we were both 13 , never met him again but have very fond memories. Also, I was raised Catholic and saint Dominic Savio,a teenager, was my favourite saint.