Check-in is generally quick and efficient. Security wait times can build up especially at the two main security check-points. Overall TSA staff courteous. The inter-terminal tram comes every three minutes. DIA has a huge variety of gift shops book stores restaurants and coffee houses though the restaurants do tend to be kind of generic. If you are planning on connecting from an international flight to a domestic flight I would recommend keeping at least a two-hour gap as customs in Denver can be a little slow but you should be able to get out in about an hour. Domestic arrival into Denver is easy as baggage generally comes quickly RTD skyride buses get you into the city for about $10. Thankfully due to the recent surge by Southwest DIA isn't dominated by United Airlines but flying out of Denver is still a little more expensive than other US airports. The architecture is stunning and the airport looks new despite being nearly 13 years old! The only negatives at this airport are the location the security lines and the alluring loneliness of the airport due to its large size.