...You havent really experienced it at all. It's not just that the English version voice acting has no emotion, the script is really generic and striped down from the Japanese version.
It just gives no feel for personality and you honestly cant even like the guys you should in the English version, because the English voice actors for Naruto, Sasuke, Rock Lee, and Orichimaru are so bad, as opposed to being amazing in the Japanese version. Yes it makes a huge difference.
http://i.imgur.com/GX2rZHa.jpg http://www.youtube.com/watch?v=rad3r9sjVSM(now epic MGS boss theme)
Its funny, I was just thinking that same thing today. I lost interest in animes for the past couple years, but watched the Naruto Shippuden episodes 200-300 in the past couple days lol in hype for this new game, and was just thinking to myself how bad Naruto's VA is compared to the Japanese one in particular.
The thing they should of done, is give naruto a new voice once shippuden started. I got nothing against flannigan but honestly he still sounds like a kid trying to act tough. Sakura also needs to sound abit older.