I also booked the Elios hotel after reading other people's reviews; however my experience of the hotel was quite different.

The room was very small, and had a small window that looked directly into the buildings next door (I could see right into their living rooms). The A/C seemed set permanently to what I estimate at about 23 degrees (ok, I am no expert, but it wasn't nice and cool!) which made the room very stuffy and musty. Even the beds were some of the hardest I have come across in Vietnam!

I was initially given a room on the 2nd floor and refused to take it (dark, old and musty, with no 'marble bathroom' as advertised, but paint chipped with an old plastic shower curtain) and then was put, with very little grace from the staff, into a room on the 4th floor. This room at least had a little more natural light....I have stayed in a few hotels in the Pham Ngu Lao area and this was, in my experience, one of the worst for the room rate.

On the plus side, the hotel has a reasonably priced roof-top restaurant with fantastic views of the district and very friendly, attentive staff (though very few patrons).

The hotel looks great from the lobby, and clearly some people are having good experiences, so my tip would be to spend a few extra dollars and get an upper floor 'suite' if you are thinking about staying there.

Another tip - after a few visits to Ho Chi Minh city, I have finally realized that it is probably better to stay a couple of blocks away from Pham Ngu Lao and walk there if you feel like it. Being in the heart of the backpacker district means that once you leave your hotel there are alot of touts asking if you want cyclo/motorbike/tour....Vietnamese touts are in no way aggressive (compared to some other SE Asia destinations), but if you don't want the hassle, stay a bit further out from this district - if you look on the map, even directly across the park from Pham Ngu Lao is a lot quieter.

As part of a 3 week Vietnam holiday in Nov-Dec, 2011, stayed here 4 nights and then a further 2 nights after a Mekong delta tour. We booked the Elios based on online reviews and it did not disappoint.
We booked a parkview room, which was upgraded for our second stay to a suite. The breakfast upstairs was good.
We walked to various markets and musuems in Hanoi and booked a Cu Chi tunnel tour through the hotel. Hotel staff were friendly and efficient.
Computers in reception area were unreliable and need upgrading.
I can recommend this hotel further.

Room was clean and decently appointed - pretty much as per the pictures on Agoda. Our room had a small barely-there window but a clean and functional bathroom.

Breakfast was of decent variety and quality - however a decent portion of it seemed to be reheated leftovers from the previous night. The restaurant also has tables on a balcony which has good views of the city.

Service was mediocre; english levels of the staff were generally poor and at times our requests to front desk were misinterpreted or not fulfilled.
We generally found front desk/bell staff to be "there" but not overly friendly (which is fine) and not particularly helpful (not fine). There was no sense of them going the extra mile for the customer. Restaurant staff and housekeeping were less English-fluent but seemed friendlier.
Our bellboy was all smiles and no service, so we didn't tip him (why, when I carried half of the bags to the car, and then from the car to the hotel?) - we saw him in the lobby every day for the rest of our stay with a sour look on his face, refusing to speak to us. Good service?

Overall, decent value for what we paid. The location is near a lot of tour agencies, minimarts, restaurants, bars and plenty of tourists. 10 minute walk from Ben Thanh market.

Stayed here for the occasion of our son's wedding. Staff are so helpful especially to help you get a taxi or to cross the road. Amazing breakfast every day and the view from the restaurant balcony on the 11th floor is fantastic.10 minutes walk to the Ben Thanh market and a cheap cheap taxi ride to the other main sites which are all fairly handy anyway. Will stay there again.