Dot net vs dot com

Hi everyone,

I have a dot com site in a foreign language that's not doing so bad in Google and I am in the process of translating it in english. I bought the dot net domain but, since I will be concentrating in english more and dot com being more popular, I was considering switching my sites: english in dot com, foreign in dot net.

Someone told me that I shouldn't do that cause I would then lose all the work I put in to improve my ranking in the past years. I just feel I might lose many visitors with a dot net domain.

Thank you all for your input.

Peter