Hello everybody!
I have been in Keilir AA in September 2012 for FAA to JAA licenses conversion, this is my impression based on my personal experience.
Pros:
-Very professional instructors;
-Excellent standardization, I have made approx 20h of flight jumping between 4 instructors and I had no problems at all.
-Excellent fleet;
-Excellent facilities;
-Icelandic CAA is very efficient: 2 or 3 days between the flight exam request and the effective date. And the day later after the flight exam I had my license.
-Free bus to Reykjanesbær and Reykjavík.
Cons:
-At that time the instructors were quite busy so I had sometimes to wait some days to fly;
-Sometimes it was difficult to communicate with the training manager. Of course nobody will push you to fly and towards the paperwork, so you have to be dynamic, make phone calls, verify every paperwork is good and done, etc...
-As Rocade wrote there is only one twin engine, so if it is in maintenance you are grounded.
-Iceland can be pretty expensive!
I was in the "short time" accommodation that is an ex military base residence. That area is semi-abandoned. There is a restaurant 1 minute walk and a supermarket 30 minutes walk. Other than that you have to take a bus ( or walk several km). The accommodation was comfortable, there is a shared big kitchen, pool, sofa study area and every 2 rooms there is one additional small kitchen and toilet. Anyway I've never had to share those facilities, probably the staff try not to put people in adjacent rooms.
From there to the airport it takes about 20 minutes walking, and if it is windy 20KT (very common) raining or snowing, you'll get wet and cold... but this is Iceland!
If you are a party dude you can go to Reykjavík, renting a car in the nearby B&B or via bus, and you'll find many clubs, restaurants, nightlife etc... but if you stay in the residence you may find yourself semi-alone. Basically it depends upon your personality whether you find it boring or not!
The Icelandic ATC system was overall very good, they let you do real IFR training (under real IFR flight plan) without many problems and letting you ask progressive clearances. Conversely once every while the Keflavík airport decided to stop all training flights for the whole day giving very short advance (sometimes no advance).
After all, my advice is, before starting, to ask for a personalized estimate based on your personal aeronautical experience (if any) to avoid misunderstandings.
Just my 2 cents!
Cheers!
B