Many violins played in modern orchestras date back to the days of Handel and Mozart; the difference is the historic orchestras use the old gut strings, so there is a lighter sound. Also they are not tuned the same. I cannot remember which way it goes, but what is say a normal B note in Handel's time is now either a B flat or B sharp today. So when you listen to a historic recording, you not only hear the gut strings, you are also listening to the music a half a note different than a modern performance. Since historic performances sound higher pitched to me, the modern tuning is probably a half note lower.
I usually prefer modern (not always). I always prefer modern instruments at the Dentist.