Some time ago there was discussion regarding this new low cost airline and I had offered to give my opinion regarding it once I had flown with it. Here is my informal review of VivaColombia airlines.
I took three flights with Viva Colombia during my two week vacation here in Colombia. I flew round trip between Medellin and Bogota and then from Medellin to Pereira. My conclusion is that this airline is a good and economical travel option as long as you build a little bit of flexibility into your plans to accomodate any potential delays (which would apply to any airline). Here are a few observations that you might find helpful:
1. In Medellin the Viva Colombia check in counter was located on the international side of the terminal but I still went through security and boarded the flight normally on the national side of the terminal.
2. In Bogota the Viva Colombia check in counter was in the main terminal and not in the Puente Aereo. I arrived early and none of the check in counters were listed for Viva Colombia. I had to ask where the check in line was because at the time it was listed for another airline until closer to my flight time.
3. There are no assigned seats on VivaColombia. You choose your own seat from whichever ones are available at the time you board the aircraft.
4. There are no free drinks or snacks on VivaColombia. The flight attendants will come through and offer them for sale, however.
5. The aircraft are Airbus A320 jet aircraft with a single aisle and three seats on each side.
In summary, the key to taking advantage of this airline's low cost airfare is flexibility. If something seems confusing at first about where you are supposed to be then just be comfortable asking questions. I had to ask where to check in both in Medellin (because it turned out to be on the international end of the terminal) and in Bogota (because it used a shared counter rather than its own, exclusive, permanent one). Other than that, as usual with flying it is best not to plan your itinerary too tightly. VivaColombia is not an exception and do not plan an itinerary that cannot absorb delays.
I hope this helps and if you have any other questions please ask!