For me; having six different barrels to choose from at a moments notice opens a whole new way to have shooting fun. These barrels can be changed in about 30 seconds with the supplied Allen wrench. So why not bring all of them to the range? The hard part is carrying all the ammo, ya think?!! I have the .22lr/22 short, .22 magnum, 380 auto, 9 mm, .357/38 and the .45/410 all in various lengths. I use the extended grips on the Snake Slayer IV and the regular length grips on the Texas Defender. The short grip lends itself to the smaller calibers (22, 22mag, 380) while the extended grip is more comfortable with my larger calibers (9mm, 357/38, 45/410).
The trigger(s) took a little getting-use-to. So the next time out, I will remove the trigger guard(s) and see if there is any shooting advantage for me. The different calibers all handle just as I expected, each with it's own size personality.

What's the "funnest"? I'm leaning toward the 45 long colt caliber. Yeah, its loud and kicks. But the more kick, the better, that's just my opinion. The 22 shorts also brought a smile to my face. If you're thinking about joining us Bond Arms derringer owners, don't hesitate. None of them cost too much. Plus, it's possible to change the entire look and versatility in less then a minute.