After using it for more than 6 months my conclusion is that the 'training status' feature is useless. The main issue is that it doesn't get basic trainingprinciples right, such as periodisation/training cycles. I guess this is because it's far too heavily focused on VO2Max. As soon as you go into a relaxed training (or -week), it goes to unproductive. Which is obviously ***, as everybody should know that sometimes you need rest and sufficient rest makes you stronger in the end. That Garmin/Firstbeat does not understand this (or are not able to properly implement this), is astonishing.
For training I can better rely on the level of my 'body battery': that's generally quite in line with my feeling and a good predictor of how my training goes.