I have a like new Beretta 92SB Compact M (single stack mag) in 9mm that I regard as a prized possession, that shoots and functions flawlessly. It seems that many are often skeptical or critical of the S&W .40 caliber cartridge compared to the .45 acp. and even the 9 mm. I, however, very much like the .40 round and have a Hi-Power and a CZ 40-P in that chambering and both pistols are accurate, powerful, dependable, comfortable, and their recoil- I consider, to be light.
I have fired a Beretta Cougar 40 cal. (if the Cougar can be considered a compact)- and have found that pistol to have all same positive characteristics. I have long hoped to own a Cougar but now may be more tempted by the Beretta PX4 Storm Pistol (available in 9mm, 40 cal, and 45 acp) which just might be something like a polymer frame reincarnation of the discontinued Cougar. I have heard that the PX4 will also be available in a sub-compact version. I like my 9mm's- but if I had to choose only one it would be a .40.