I guess product loyalty, being a Sporlan man I hardly looked any further until one of vendors started to carry them and rec them.. We don't carry many parts on our trucks they changed to a min inventory many years ago. Just run and gun.. If I were to stock a truck these would be a good choice for txvs as you stated. I do like the small size ,they seem a little cheap at first compared to other valves but as long as they function and hold up.