Flexmls is the one chosen by the Aspen/ Glenwood Springs mls and Boards of Realtors as the mls provider. It is the most up-to-date! I can use it to email or text my clients homes they may be interested in. One of my favorite features is subscription searches. If you are invited to a portal, set it up!
Find tips about using Flexmls here.
Flex mls has an RPR plugin. RPR stands for Realtors Property Resource.
This tool allows for rich comparative analyses. I would go to the app store and download the consumer facing version today!