Somehow, "sophisticated" has quite a few definition in Chinese which are quite different in meanings. Maybe you can show the "sophisticated" that you want to be translate in context?

I would say, "中文蘊藏豐富文化內涵，非常優美。" 寫出這句話的時候真的非用繁體不可，否則就是太虛僞了: 既然這麽好，為甚麽又要把它砍得殘缺不全? A literal translation would be all wrong in syntax and meaning. 中英文都好的人着实不多，翻译到信、雅、达的标准，殊不容易。

1.复杂的 2.有经验的，世故的 3.先进的 for reference only

it depends on context of the expression.