I agree 100%. The first thing I would ever do to a car with bad all season tires was swap for summers. It makes a WORLD of difference...Your tires are the single most important feature on your vehicle. Some will argue, its the engine, some will argue its the suspension, etc, etc.
These people are all wrong. Your tires are the most important for the very fact that they are the main suspension linkage that connects your car to the ground. Changing diameter of tire will drastically affect vehicle dynamics and how your car behaves.
If you've gone with bigger wheels/tires, and your ride is more harsh, I'm assuming your going with low profile tires. Side wall thickness plays a big part in your ride. The less side wall you have, the stiffer the tire, the more harsh your ride.
Swapping out for softer springs will only use up your suspension travel unless you get a proper damper for the softer springs so your jounce and rebound aren't ridiculously misaligned relative to your spring rates.
If your that worried about your ride then lowering your tire pressure by a couple of psi might help but I don't know how noticeable this would be, and how worth it due to premature wear on your tire.