I agree with my colleague. Once the visa stamp expires in your passport, even after applying for an extension within the US with the USCIS, you will still need to attend an interview at a consulate or embassy to have a new visa stamped into your passport to permit you to enter the US. If you travel frequently, renewing outside of the US definitely makes more sense, as the extension within the US only extends your existing I-94 stay.
A renewal of an existing visa stamp is a new visa stamp.
The Court of Appeals for the Eigth Circuit has stated that "immigration laws and precedents are complex."
You should retain an experienced immigration lawyer to review all the facts, advise you, and handle the case. You can find one through http://www.ailalawyer.com.
J Charles Ferrari Eng & Nishimura 213.622.2255 The statement above is general in nature and does not constitute legal advice, as not all the facts are known. You should retain an attorney to review all the facts specific to your case in order to receive advise specific to your case. The statement above does not create an attorney/client relationship. Answers on Avvo can only be general ones, as specific answers would require knowledge of all the facts. As such, they may or may not apply to the question.
Do you mean extending your E2 status in the U.S. vs. obtaining a new E2 visa stamp at the U.S. embassy? Go to the embassy for a renewal of your E2. Its true that generally its easier to get the E2 status extended via USCIS, HOWEVER, it doesn't really make sense, since you will have to submit an entirely new E2 application at the U.S. embassy next time you travel outside the U.S. The embassy will not take into account that your status was extended in the U.S. In fact, in my experience, embassies don't like it too much when you extend your E2 in the U.S. instead of with them. If you are doing your E2 on your own, I strongly suggest you get an attorney ASAP! And I say that having had to clean up many denied E2 extension requests.