A 45 aspect ratio tyre is no longer considered very low profile by modern standards but that doesn't make them the best thing in my book. They ride harder and the rims are more subject to pot hole damage. People think they look good which is fine, to each there own as long they don't complain about the consequences.
45's on 17" are not that bad but they would be my absolute limit. The trend to ever larger wheels and even lower profile tyres is simply a stupid fashion fad that puts form before function. Meanwhile I'm miles behind that trend with 205/55/R16's and very happy with the excellent ride quality they provide.
I haven't had a car that could accomodate 16" wheels since 2013, so 17" it must be for me.