Not so much .. as ..

Dear all,

I just used this expression in a mail: "I am not so much worried as perplexed." Although I know this sentence is grammatical, I am not sure at all if this sentence is easily understood in a casual conversation. How do you native speakers think? I would appreciate your opinions!

One more thing: if I say, "I am not so much worried, but perplexed," does it make sense?

I am looking forward to your opinions! Thanks a lot