Welcome Steven;
There were many discussions about all the subjects you have asked about, mainly in this same discussion area.
Unsure what you mean by "luger specific"? Lugers were made prior to ww1, then ww1, then into the weimar era, and ww2 era, and finally from 1970 approx on for the newer guns.
Disadvatange to carrying concealed, size, cost, reliability... Lugers can be reliable, but to me a 1911 clone is more so, let alone many newer (but ugly guns
) like a glock...
ED