Yeah, I think tractor size comes into play also. When you get up above 50HP the uses of the tractor tend to change.
I don't mean to offend anyone so am giving my disclaimer up front. No arguments desired. Just my opinion. Tractors in the CUT size and down are generally used for light chore work and small tasks. 90% of their life is spent doing tasks that they easily handle. Repetitive, low power requirement tasks. In that World HST shines.
Large CUT tractors and up into the Utility or AG class tractors are generally used for heavy FEL work, medium duty chore work (carrying two big bales) and larger occasional ground engagement tasks. 90% of their life is spent doing tasks that require their power and weight. Monotonous, grueling taks. In that World Shuttle shines.
Not a bad way of looking at it! For the most part the distance and the job at hand determine which machine I run. My DK40 is the largest HST I would really want and I would have probably got a shuttle if it wasn't for the other half wanting to use it for some of her things as well.