I personally like the new grip texture, backstrap and mag release.
The triggers all seem the same to me, but I also swap them out for glock 17 triggers because I prefer a smooth face.
I noticed that the gen4 26 trigger had a small bump towards the top of the arm that cocks the striker back. I'm not sure what this about, but the trigger pull did seem heavier on the break than my other glocks. But once I start running the gun, I don't notice.
I've owned a gen g17 and I still own both a gen4 19 and gen4 26. I like them all.
I like the shape of the new backstraps with no backstraps installed. I'm really glad and I knew that when I bought them. The backstraps when in stalled seem like a cheesy aftermarket add-on (as a matter of fact, there are already cheesy aftermarket parts that slip on back there). They just feel cheap and poorly executed. I don't use them so it really isn't an issue for me.
The mag release is perfect for me, I'm glad it is wider and requires a bit less of a reach.
The texture on the grip is great. I'm a 1911 guy at heart, so I like an aggressive grip. The previous rtf2 grip was awesome, but the texture cause cotton polo's to stick to it and give new meaning to "printing." The gen4 grip is aggressive, but not overly so.