I'm about to be carrying a SIG 226 .40 for work.  That's fine and good.  However, when I'm going CCW, I'd like to have something a little smaller.  I want to keep with SIG, since it's controls dont translate to many other pistols.  But that's not the issue.  If I get a 229, I have same ammo and 12 round mags.  If I go with the 239, I have a marginally slimmer grip and same ammo.  If I go with the 245, I have different ammo and mags, but a real thumper.

I'm leaning towards the 229, simply because of ammo.  However, I do have a bit o' .45 on hand, so the 245 is not really too much of a problem.

BTW - anyone buy any of the 229's from CDNN?  $389 for VG to Exc....  I'd like to see how they function, looks not too important...

The 229 will not only have 12 Rnds but feel very similar to your 226 for fast target acquisition and rapid follow-up shots.

For the 239, I suggest you first test shoot a 239 and make sure it feels good to you and you are able to do rapid fire comfortably. Also, I AM Not able to rapid fire the 239 quickly/accurately Unless it has the Hogue finger grove grips. If you like the 239, please try those Hogue's, they make a world of difference to me..

Check out Ordnance Outsellers for thier CPO Sigs which run about $450. It's a little more than CDNN but they are in excellent condition and OO stands behind the product.

As for the choice, I would definately go with the 229 in .40.

I tend to agree with the 229.  Capacity is superior and there are a lot of .40 S&W rounds out there that pack more punch than a .45 through a barrel of that length.  My local PD uses 229 .40 S&W's for duty use.  Personally, I'd probably pick the 229 in .357 Sig but that's just me.  I love that round.  Less whip than the .40.  MJD

Thats easy....229! Hits harder then a lot of 45's and the slide is 1 solid milled piece! The strongest .40 ever made.