I still love my G17G4. It has functioned perfectly, was built on my birthday, and I think having a G17 in the stable as the "staple" Glock is its own reward.
That said, I love the G45 too. Starting from scratch you probably only need one or the other. I think it boils down to personal preference. Same reason I own a 4" M2.0 and 5" M2.0 and can't really justify the extra 400-500 for a 4.25" fullsize.