How Much Does Wheel and Tyre Affect Ride Comfort

[lazy]

I'm wondering if anyone has any experience going from 17's to 18's, and touring tyres to sports tyres.
I'm probably due a new set of tyres this year and I think the 18 Monzas would look good but I don't want to sacrifice ride comfort really so I'm wondering if it's a big difference going from 17's to 18's.
Also I'm wondering if there's a big difference in comfort between tyre styles for example Continental Premium Contact versus Sport Contact.
Any input would be greatly received.

[MKVASMR]

I use 16" for winter and I don't feel much difference when I go back to 18" in summer.

[lazy]

I definitely thought that would be quite noticeable.
How are the roads where you live quite smooth or pretty rough, I have to say they're quite rough where I am.

[ArkadyPaul]

The ride is definitely softer on 17” tyres, the increase in sidewall should always improve the comfort level, albeit with a slight deterioration in handling.