Having a 401 matching is much recommended. I've written a detailed post about how it is good for NRIs here.
And yes if you are an NRI, having an NRE account is essential in my opinion. Because it will be easier for you show your sources. If you are sending your money to other accounts, they won't be counted as "NRI money". For example if you want to take a home loan in India and want to show your source if income, you need to show it in your NRE account.
Hope that helps.