I know a bunch of folks that use them for 38 Super and they love them... But, I'm not sure you really need to process 9mm or 45 for that matter.. if you are using an unsupported barrel or range brass then you'd see some benefit in using it for 40...
He high pressure rounds tend to distort the brass and some of the folks using 38 super and 38 super comp in IPSC have a tendancy to push these rounds hard...
I often wonder if the rounds that these guys shoot would go back into the chamber without resizing.. they leave the barrel hot and would have expanded to the chamber on firing and with the pressure they use would the case not want to continue expanding as the round is ejected (after all pressure is what pushed the slide back so the case is under pressure (enough to expand it a little?)
I was beaned by a 9X23 or 9x21 a while ago and it hurt and friggin hot...