Honestly, I doubt anything is more comfortable than stock in a straight line.
With regards to turning, I am personally more comfortable with a certain amount of control (lean is discomforting to me), but if you're talking about bump absorption etc., the stock springs are likely to be your best bet, once again.
Perhaps someone else might know of something softer, but I doubt there's any springs out that will Camry-ize your tC's ride.
-Ed