Pullout desk was an option that was available from factory prior to the 2018 model years. However in 2018 it was made standard. That being said there were some early 2018 models (late 2017 delivery) that were really just 2017 models. They had the old interior wood/floor colors and did not have the W/D prep.
So if you are comparing 2018 models and it doesn’t have the pullout desk than you are looking at the early models and probably have the older interior color as well. Unless it was ordered with the desk.
The front bunk (if I remember correctly) was 200lbs. However if I am wrong than it was 250lbs. RV is in storage right now.
Regarding new vs old revision easiest way to tell is by the floor. Plank style is the older version and herringbone is the new version. Photo below shows 2018 on Left and “2017” on Right