As you may have heard, the team from Remote Satellite Systems (RSS), which like UAH has a model that attempts to calculate atmospheric temperatures, has a new version for the lower troposphere, version 4.0, upgraded from version 3.3.
Here's their paper describing the changes.
You can read more about all this from Nick Stokes, here and here.
Personally I'm not interested in getting too far into the details, except to note that the changes are pretty big, especially after 2000:
RSS v4.0's trend for the lower troposphere is now +0.18 C/decade, compared to UAH v6.0's trend of +0.12 C/decade. That adds up over almost four decades, and again puts UAH at the outlier (when compared to GISS, NOAA, HadCRUT4, JMO and Cowtan & Way measuring surface temperatures).