The only perk to a j frame would be that you don't have to worry about a slide cycling if you had to fire it from your pocket and possibly short stroking. That'd be a pretty lousy day if you had to do that, but there have been a few accounts of needing to. You may very well be better off with a knife in that situation... but that's a pretty extreme scenario to look at.
That being said, as far as weight and concealibilty, the LCP wins hands down. It's lighter and thinner, so it doesn't pull on clothing or print very much, if at all.
That being said, as far as weight and concealibilty, the LCP wins hands down. It's lighter and thinner, so it doesn't pull on clothing or print very much, if at all.