First of all, do not book this hotel if you want to be in Panama City. It's far outside the city (about a 10-20 dollar cab ride depending on how you bargain). Second, the location is not great at all - its surounded by strip malls and a highway passes right by. If you want a more authentic rainforest experience I would suggest the Gamboa Rainforest Resort.
We booked a double and it was very large and had two double beds. The room was very sterile down to the tiles which were absolutely freezing every time you got out of bed. Also it looked out on a pile of dirt - not exactly picture perfect.
As for the staff, they tried to be helpful but were very incompetent. The morning we checked out the front desk called our room 10 times because they had forgotten details we had told them about a taxi we needed. The taxi didn't even come at the right time - it came 2 hours early. I speak Spanish and I imagine I would have had even more trouble in English since the staff spoke only rudimentary English at best.
Also, a personal pet peeve was that there was no wireless internet, despite the fact that they advertise as having it. We had to pay $5 to get a cable to connect to the internet that way.
Final advice - there is no bank or atm near this hotel so make sure you have cash if you need it before you come. Otherwise you have to get a cab to go to the bank/atm next to El Rey.

We've stayed at other Avalon resorts, and this one was something other than what we expected, even after reading all of the reviews before going.

Let's start with the positives:

1. Hotel staff was great, very friendly (even though I had trouble communicating most of the time due to my limited Spanish).
2. Food was good.
3. Grounds were fun to explore, the water park was fun to watch/enjoy on the weekend and the hanging bridge in the back was a hoot.
4. I go to the ATM, and US dollars come out! Was hard to even get Balboas.
5. Get out and see Calle Ureguay (nightlife, clubs), the Causway Amador (great place to get away to during one of your days), and Valle Del Anton (long drive getting there but rather interesting in my opinion, and you get to see some of the country and the mountains while going there). I've likely mispelled all of those.
6. Weather was fantastic, it was the dry season in March.
7. View from hotel of the mountains and countryside was really great - make sure you get a room with a view.
8. Our cab driver Enrique was the man, got us everywhere safe and sound!

Now the negatives:

1. Hotel was very moldy, as others reported.
2. Hotel was rather boring believe it or not. See next item which may be the reason why...
3. This hotel is used more by locals and business folk then actual vacationers.
4. If you only speak English and are shaky with your Spanish (or know no Spanish at all) you're likely going to be very uncomfortable here. There's always someone at the front desk that knows enough English to get you what you need, but other than that it's touch and go. Brush up on your Spanish or carry a pocket guide.
5. The water park would be empty if it wasn't flooded with locals on the weekends. This is a pro and a con, but to be honest it was rather amusing to watch and we did test out the lazy river. The water park has a separate entrance from the rest of the grounds so most of the folks just going there for the water park don't come through the hotel or the upper grounds which keeps things quiet.

That's all my opinion. Bottom line I think this is a fine place to stay for families, and it's fine for couples looking for a deal that don't mind having to cab it off the resort for something to do.

We stayed at the Avalon. The room was spacious, it was away from the busy streets secluded in trees which was nice.

the trip to panama was awsome.
the resort has many issues.
lots of employees standing around doing nothing.
i had to clean the pool myself when i used it.
the resort needs alot of clean up all over
it is sad, because at one time someone paid alot of money building this resort and the grounds.
now the management is just letting it run down.
i brought several issues to managements attention,
but nothing happens.
the bellman solicited prostitution to me..
has lots of room for improvement.
then on thursday and friday night there was a conference.
the kids partied all night long for 2 nights.
i spoke with front desk and management and never got any resolve...
hot tub and sauna broken down,
on and on and on.......