My aluminum frame road bike would rattle the teeth out of your head with 23mm tires pumped up to 110-120 psi (i.e. Old School). Finally saw the light and moved up to 25mm tires (biggest that will fit) and lowered the front to ~70 psi and the rear at 110 psi (I used an online calculator, entered my weight, and got those pressures). Night and day. Bike rides much nicer now (though still no Cadillac) and turns much quicker.

Ride lots of different bikes at the local bike stores to get a feel for them. Make sure the pressures are adjusted correctly, it makes a huge difference. Buy the bike that feels best to you.