It’s more about feel...you know...the purchase that your hand makes on the weapon. The tool should be an extension of your hand and you should really be able to point and shoot it.
It’s my opinion that you are better off to spend more for a weapon you feel comfortable with, that you will carry every day just like your wallet or watch and that you are willing to spend the trigger time developing your skills with it.
If the purchase is uncomfortable, if it is cumbersome and bulky to carry and if it’s miserable to shoot you’ll find yourself unarmed most of the time. And that defeats the purpose of it doesn’t it.
Also, if you aren’t sure or don’t know, you need to learn how to draw the weapon from the holster and get it on target and double tap that target. Handgun stopping power in the real world is abysmal.
One training scenario I use is 4 paper plate targets about 7 yards down range, spread out at a reasonable distance. Then I draw and double tap each target. If you can get two hits on the plate at that distance, you can call yourself proficient with a hand gun. You can move the targets further away, but be aware that in some states if the target is more than about 7 yards out it can’t be considered self defense.
You just can’t practice enough. There are some very good and very poor training videos out there. I have probably 12 on DVD and I refer to them to use different drills for different skills.
Once you start shooting different weapons it will be much easier to know what is best for you. An FYI. Unless S&W has done some trigger updates on the SV line (which are Glock copies for the most part) they have a 15 plus pound trigger pull. You can tune them up for a fine trigger pull. The powers that be at S&W screwed that weapon up because they thought anyone buying a weapon like that would want a double action 15 plus pull, but I hate it. It is easily remedied.
Just random thoughts.