If you plan on conceal carrying a pistol, ounces and fractions of inches do make a huge difference. Even the P229 is a heavy pistol to carry all day long.
I’m in the “not much difference in size between the two” camp. I have both and like them both. I wish that sig had abbreviated the grip more as that would have made it much more concealable. I prefer the 226. Just a better shooter for me. My MK25 is an absolute laser. One of my few guns that I can do the whole, “I know I pulled that one just a bit...look and it is exactly there; thing.” It is squared away enough that it really reveals my flaws.
Surfer