For me its the platform over the caliber argument...
I own a variety of 1911's ( 4" and 5" guns ) in 9mm and .45 acp...and I'll take a 1911 in either caliber over anything else ! A 1911 from Wilson Combat in 9mm ( a 5" all stainless gun ) is hands down one of the top 5 guns in my safe...
Top 5 handguns in my safe ( in no particular order ) because I change my mind every week:
a. Wilson Combat 5" 1911 in 9mm
b. Wilson Combat 5" 1911 in .45 acp
c. Sig Sauer X-Five in .40S&W
d. S&W model 27-2 4" revolver, .357 mag, Nickel finish
e. Freedom Arms, mod 83, 5 shot single action revolver in 4 3/4" barrel / .357 mag ...its a new addition ( and right now I can't go to the range without it ).
and I'm leaving out some darn fine guns ....an Ed Brown 1911, some other S&W revolvers in model 18's, 19's, 29's...some nice rim fires..even some Sig Sauer 226's ...