Sure. So for me, the G4 handle seemed crowded, unless I use the the finger choil. The 4.5 is MUCH different! I would say the handle is a little long, but very comfortable, so you have plenty of handle. You can choke up or choke back and it is comfortable. Reverse grip does not feel very good to me on the G4, but does on the G4.5.
I have a hard time describing handle comfort, but I will say I prefer the 4.5. It has more of the all around woods/bush knife handle. Similar, but not the same as, Survive GSO 4.1, CPK Field knife, and maybe a little bit like a Bark Rive Bravo 1 LT, but more like the other two. I do prefer the GSO 4.1 and CPK Field knife handles more, but it is up there with them with comfort. It doesn't fill the hand quite as good, but is comfortable, to me.
Also, I usually don't like jimping, but really like the jimping on it. It is the same as the G4.