The S&W 469 and 669 are 2nd generation guns. There is a reason that S&W revised and came out with the 3rd generation, and I would suggest you stick with the 6906 or 6904. This gun fits my hand just right and shoots better than I can.
If you get a 690x with the older squared off trigger guard, you will have a much harder time getting a holster to fit the gun. Trust me, I know, I know. Mine rides in a holster that was made for the 469 series and this works OK for me.
Call CDNN
soon since last week I saw an ad by them showing some 690x models for sale. It is a great gun and you can also use the full-sized magazine from the Model 59/590x series of guns.
Assuming you can find any double-stack magazines anywhere
Bart Noir