Out of boredom, I looking into these conversions a bit. The onlything I can think of it being useful for me is for hiking/camping/outdoors-ing. I'd get the basic model, a colapsable stock, and fixed sights. This would get me a compact unit that could be attached to my pack, keeping weight down, but allow me to turn the 1911 on my belt into a rifle, while keeping the bulk of my gear to a minimum. Price for this? 459.85 for the bare-bones, no thrills.
Thats $500 (with shipping and all) for something that does absolutely nothing. I still need a 1911 (or Glock) to do anything with it.
I could get a used Marlin or Legacy arms for less, my local shop usually has them in for $350-500. I could get a Hi Point Carbine for ~$250, which apparenty is coming out with a .45acp model, as well as their 9mm.
If these conversions could be had for ~$200-250, I might be inclinded to get one to save on weight. The only use I see of these, for the money, is as mapsjanhere has said.
“There are three reasons to own a gun. To protect yourself and your family, to hunt dangerous and delicious animals, and to keep the King of England out of your face.” - Krusty the Clown