anybody rocking conversion pistols?

I just found out that a company called EFK made a 40 super barrel for a gun I have. I had never heard of the 40 super round but after some reading it seems like a good deal. It's a necked down .45 that lists specs that rival 10mm. While I don't really have a real need for the round It just ticks all the right marks.

I see various conversions for .22, 9mm, and a handful of other ammo. I always wondered how those worked out for people. I think k would be nice to has a firearm than can shoot .45, .40, 9mm, and 22lr with just a few part swaps.