As far as durability goes. I don't think that sould even be considered when buying a sig or Beretta. But the Beretta just works better for me fit and finish, over 5k and no FTF or FTE.
I also had both (92FS and P226) and I liked the Beretta alot but when it came time to sell a gun, I couldn't let go of the Sig. The trigger is sweet, the fit is perfect and the Sig just looks cooler. I think both were equally accurate.
I've had both (multiple M9s in the Army and a SigSauer P228). 3/4 of the M9s I was issued were jam-o-matics. The P228 ran perfectly, but felt wierd to me.
So of the two, I'd choose... option #3, a CZ-75B. I'm picking up mine tomorrow.
On a more serious note, both are good guns. Commercial Berettas have an excellent reputation, as does the SigSauer. Handle a bunch of different models and find what suits you best.