I have a Glock 23C and a Sig P-226 (both .357 Sig and .40 S&W barrels). In my opinion, there is no comparison -- the P-226 is superior is every category: accuracy, manufacturing and materials quality, durability, reliability, etc.
I am frankly surprised that the P-226 has not been recommended in this thread. It is a full-sized autoloader, but certainly not too large for concealed carry. Also, it is ACCURATE and exceptionally well designed and fabricated.