Had a Gen 3 19 for years. When the Gen 4 came out I wasn't impressed enough to upgrade. Gen 5s however are meaningfully better, in my opinion. Had 2 until that darned boating accident!
I still like the gen 3 the best
3s were good. I like the texturing and lack of finger grooves on the 5. Think the trigger is much improved as well.
Bore size is no substitute for shot placement and Power is no substitute for bullet performance. 458WIN