Looking to switch from a Mazda to Lexus

Hey everyone, I’m looking to switch out of my ‘21 Mazda 3 Turbo into a more comfortable and reliable car. The question I have is a 2013-16 GS350 vs a 2014-17 IS350, around $22-25k

The IS is closer to the size/handling of my Mazda, planning on kids but I am not worried about the size because I’ve transported my niece/nephew tons of times in their seats.

The GS’s are much harder to find with good mileage, and are 7 inches longer, but I hear they handle extremely well for the size.

I plan on test driving a GS Friday or Saturday, and I have test drove the IS. It was more comfortable, and less fun, which makes me feel good about keeping to very high mileage.

Does anyone have any thoughts on which, knowing I love fun as much as reliability?