Good point about the wheel/tire sizing playing a role in the overall ride. It's a different effect from the springs and dampers, but important nonetheless. I switched to 18" before getting my coilovers, and that definitely improved the ride, but it didn't transform the ride like changing out the suspension did.
The ride and handling balance with taller tire sidewalls (245/45R18) + stiff-ish sporty coilovers (8kg/11kg Redwood Performance Sport) feels great to me. To get the same ride with the stock wheel/tire setup you'd have to go softer on the suspension, and that's a poor tradeoff. Taller sidewall + sportier suspension is the better and more practical combo in my opinion.
(Of course if you just gotta look good with big wheels, no worries, sometimes that cost has to be paid.
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