I should tell first that you could do a combination of both.  Note: Check IRS publication 590 to see if you are with in income qualification before you try it however. 

Vanguard will let you start an account in index fund at 3000$. 

There is one major advantage to having a Roth account.  You can withdraw you initial invest at any time with out penalties.  Do read all the term of the account before try to do this.

Do you have an emergency savings account?  I don’t use my Roth account for this but you can save money in a bank FDIC insured Money Market or CD account with in a Roth IRA.  Banks like Bank of America and Citi Bank have it.  I would think that most banks would do the same.  It would be great to earn intrest tax free for your emergency account however you would have to leave the interest in there for 5 years.  Check the term of Roth before trying this.

Oh yes forgot to tell you can start a IRA at a bank for as little as 50$.  Once you build it up to say 3K$ you can transfer directly to mutual fund company like Vanguard.  Check with Mutual Fund Company before transferring assets.

Remember that money that is put in to your deferred account is about 50% larger to compensate for the taxes that are not taken when you try to compare it to a Roth account.

Just for fun calculate your taxes with both account just to see what I would be like.

The main advantage with the differed compensation account is dollar cost averaging.  You can make small buys (like 20$) ever payday automatically.  This tends to smooth out the highs and low of the market over time.  

Note: There are extremely high tax penalties for withdraws for deferred account and some like my 457 there is no loan provision. 

Note: There are some legal protection for 457 accounts   (I am not sure so please check) under lawsuits and bankruptcy