Tony in Salt Lake wrote a review of Primus EtaPower EF with 2.1L Pot/Fry Pan Lid and Storage on August 20, 2012
The thing I love most about this stove is how efficient it is; making a canister of gas last twice as long. I normally carry two canisters of gas but I have yet to use the second canister on multi-day excursions. This is most likely due to the heat exchanger of the pot. The other great thing about this stove is it's ability to control the flame. It's easy to keep a low simmer going or a violent rolling boil. It packs up nicely and is sufficient for two people.
One problem I have had with this stove is very fine sand got inside the piezo ignitor making it inoperable. But, I was able to blow the sand out and it function normally.