Nice and cool choice for your first semi-auto. Congrats!
Sure, the interchangeable grip options are a nice feature with that gun, so you CAN make the gun fit your hand, whereas many guns (especially larger framed semis) force the shooter to adapt to the gun. (Hand movement.)
I think along with comfort and grip while shooting, you should consider the balance that also includes grip and accessibility to the gun. (Mag release button, slide stop etc.) That's one very cool aspect those interchangeable grip options provide: you should be able to operate/use your new gun with minimal "hand travel" around and behind the gun with your strong/shooting hand.
Since most guns do not provide this adaptability feature, shooters are required to "break their grip" from a high/firm shooting grip, to come around the side of the gun somewhat in order to access the gun's controls. This isn't necessarily a "bad thing", especially with adequate and effective training - BUT - it sure is nice if you don't HAVE to do this with every mag transition, or simply locking the slide to the rear. Hope this helps, and I hope you can find that ideal fit and balance with your new gun.
Congrats again, and share some pics of your new baby when you can - :biggrin: