XM203 is ugly. Classic M203 all the way.
Expensive it definitely is. $300-350 for the launcher and then another $400-500 for grenades. But definitely worth it. Takes alittle practice, especially the propane grenades that have alittle less power (but are cheaper and you don't have to lug along multiple gas sources). And it does make the gun front heavy, especially if you're not running a full stock and have the battery in the front. But definitely worth it!