I really think you will see a bunch of Glock purist dumping the other 380's and jumping for this, just my thought. I'm not a Glock can and have no intention on purchasing one of these, unless my dept allows it for a backup, which is highly unlikely.
Would you carry it as a backup? Taking into consideration I'm not LE, when I carry a backup, it has to be concealed, I go with a j-frame revolver (M&P 340) with .38+p. I am just as good (bad) a shot with that as a .380 pocket gun, but with almost equal comfort in concealing, I go with the larger round. What do you use now? I imagine if concealability is not a factor, I would want something with common mags, i.e. Glock 22 & 27.
Speaking to a small number of active LE, many times at GT, I find that the S&W Bodyguard .380 and/or Shield 9mm or .40S&W are popular, for reasons I can certainly understand. I'm just not sure where the 42 fits in. Seems like a pure Glock fanboy toy.
On a side note, my thoughts on the Glock 41? Yes, please.