As you know the Glock Gen 4's have backstrap attachments for the handle that can change the thickness based on your preference. After playing with them I found the medium to be a good fit. I was a little aprehensive about how well the attachment would be on these grips but once installed there is no play or wiggle. It feels like part of the gun, so good job on that option by Glock.
I tried out a few IWB holsters and the one I liked the most was a BladeTech Phantom, despite the lower cost it has. It's not kydex but the plastic is firm enough nothing will tamper with the trigger but it's a little softer than kydex so it was more comfortable up against the body as it does have a little give to it. Time will tell of course after a lot of use how good it really is or isn't.
I am planning to also get an OWB holster. That one will be kydex and I am still trying to figure out the one I want to go with and also if I will get a tactical light as well. Decisions decisions...
Only upgrade I have planned at this time is to take off the factory sights and put something better on. I haven't shot this gun yet so no real feedback at this time as to its performance. But as for the feel and size I can see why this size is so popular. It definitely seems like the best of all worlds in a handgun.
I'll post updates a long the way as I use it more. If any of you have good sight recommendations I would love to hear them and your experiences.
Thanks for looking