I think that is really going to depend on each issue and its current value. Be sure to take note of this:
Treasury guarantees that an EE Bond (whether paper bought at half of face value or electronic bought at full face value) will be worth at least double its purchase price when the bond reaches original maturity. Original maturity is a point part way into the bond's 30 year life.
For EE Bonds with issue dates from May 1, 1997 through May 1, 2003, original maturity is 17 years after the issue date.
For EE Bonds with issue dates from June 1, 2003 through April 1, 2005, original maturity is 20 years after the issue date.
This is a very important aspect of EE bonds in a low interest rate environment. Once they hit maturity they immediately acquire face value even if they haven't gotten there yet based on interest accumulation. So depending on the interest rate history of the bond you may very much want to at least hold them to maturity.
Next, EE bonds are very different from nominal Treasuries in that they don't have interest rate risk - that is their value doesn't decline in a rising interest rate environment. Right now with extremely low interest rates and QE planned to be scaled back that needs to be factored into the equation. Also, be aware of the difference between bond funds and individual bonds - they behave differently. Individual bonds have a guaranteed face value at maturity, bond funds do not. This is another consideration in a environment where interest rates may rise (note the use of "may" really no one knows what will happen).
It is complicated. But consider that right now EE bonds even at 0% might be a good buy. Why? Because of the guaranteed doubling at maturity. That means new EE bonds have 3.53% yield if held to the full 20 years and yet also a certain degree of short term principle protection not found in a long term treasury that is subject to interest rate risk.
Sorry if that is a long and complicated answer but your question is very, very much a "it depends" kind of thing. And you must be very careful when comparing savings bonds to treasury bonds to bond funds. They are all actually rather different instruments.