What do you all think about chip tuning?

I have already searched the forum and found one or the other, but I still haven’t found a clear answer to it. Can you recommend a chip tuning or not. I hope I will get my Civic 2.2 executive in the second June week. And do you have addresses, perhaps in Hannover?? What happens if a warranty case occurs? Do I have to leave the car where I have provided it with a chip? Many DANK for the answers…