l think the G37S is amazing, but a smooth ride is a big issue for me. l heard that the G37S was a little rougher do to the suspension. is this true? is it that big a difference? should l be safe and not splurge for the sport?

If a smooth ride is important, stick with the G37. Sport suspensions are more racing than enjoyment.

You answered your own question.

Sport cars with sport suspensions will fell bumps more than a luxury car with a luxury suspension. For example a corvette will have a fairly bumpy ride. So basically the more sporty and better handling the car is the more bumps you will feel.

If smooth ride is ''big issue'' than definitely not the Sport model, maybe not even the Infiniti as the base model may be too stiff for your ''cushy'' taste. You may want to take a test drive on some rough roads. The Infiniti has always been tuned to a ''BMW'' type ride - handling is more important than smooth ride. The Lexus has been tuned more for the smooth ride as first and handling a close second.