No, it's one of the worst.
And my advice would be to watch out for illegal R4 flash carts. Not only are they unreliable, but owning one could see you in a lot of trouble.
Recently, a judge in Japan rules that makers of illegal flash carts must pay back millions of dollars, and I wouldn't be surprised if the system tries to deter consumers by handing out heavy fines too!
You can read more about the fines handed out to illegal R4 flashcart developers here: http://uk.gamespot.com/news/nintendo-wins-1m-in-damages-from-illegal-flashcart-sellers-6411201